function ProblemSolver() {

    this.dp = function( i , hand ) {
        var res , r1 , ret , a , b , c , d , j;
        if( i < 2 ) {
            return 0;
        }
        if( hand > this.lim1 ) {
            res = ( 1 << 23 );
            return res;
        }
        ret = this.done[ i ][ hand ];
        res = this.memo[ i ][ hand ];
        if( ret == this.cc ) {
            return res;
        }
        this.done[ i ][ hand ] = this.cc;
        if( this.arr[ i ] == 0 ) {
            res = this.dp( i - 1 , hand );
            this.memo[ i ][ hand ] = res;
            return res;
        }
        res = ( 1 << 23 );
        a = this.arr[ i ];
        b = Math.floor( a / this.k );
        c = a - ( b * this.k );
        if( c != 0 ) {
            if( hand >= c ) {
                d = 2 * ( i - 1 ) * b;
                r1 = this.dp( i - 1 , hand - c ) + d;
                res = Math.min( res , r1 );
            }
            else {
                b++;
                d = 2 * ( i - 1 ) * b;
                c = c - hand;
                r1 = this.dp( i - 1 , this.k - c ) + d;
                res = Math.min( res , r1 );
            }
        }
        else {
            d = 2 * ( i - 1 ) * b;
            r1 = this.dp( i - 1 , hand ) + d;
            res = Math.min( res , r1 );
        }
        this.memo[ i ][ hand ] = res;
        return res;
    };

    this.solveCase = function() {
        var res , i , j , a , b , c , d , e , hand , ma , prev , cur , inf;
        res = 0;
        inf = ( 1 << 23 );
        ma = -1;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a;
            }
        }
        if( ma > 500 ) {
            res = this.dp( 500 , 0 );
        }
        if( ma > 1000 ) {
            res = this.dp( 1000 , 0 );
        }
        if( ma > 1500 ) {
            res = this.dp( 1500 , 0 );
        }
        res = this.dp( ma , 0 );
        print( res );
    };

    this.solveCaseGreedy = function() {
        var res , i , j , a , b , c , d , e , hand , ma;
        res = 0;
        ma = -1;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a;
            }
        }
        hand = 0;
        for( i = ma ; i >= 2 ; i-- ) {
            if( this.arr[ i ] == 0 ) {
                continue;
            }
            if( hand < this.arr[ i ] ) {
                this.arr[ i ] -= hand;
                hand = 0;
            }
            else {
                hand -= this.arr[ i ];
                continue;
            }
            a = this.arr[ i ];
            b = Math.floor( a / this.k );
            c = b * ( i - 1 ) * 2;
            res += c;
            d = this.arr[ i ] - ( b * this.k );
            if( d > 0 ) {
                c = 1 * ( i - 1 ) * 2;
                res += c;
            }
            hand += d;
        }
        print( res );
    };

    this.getInput = function( irObj ) {
        var hasMoreInput , i;
        hasMoreInput = true;
        try {
            this.n = irObj.nextInt();
            this.k = irObj.nextInt();
            for( i = 0 ; i < this.n ; i++ ) {
                this.brr[ i ] = irObj.nextInt();
            }
        }
        catch( ex ) {
            hasMoreInput = false;
        }
        return hasMoreInput;
    };

    this.clearArraysPerCase = function() {
        var i , j;
        this.arr = new Array();
        this.brr = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
    };

    this.clearPerCase = function() {
        this.cn = 0;
        this.cc++;
        this.clearArraysPerCase();
    };

    this.HAS_TEST_CASES = false;
    this.INPUT_FILE_NAME = "test.in";
    this.OUTPUT_FILE_NAME = "out.txt";
    this.DO_OUTPUT_TO_FILE = false;

    this.declareAndFillArrays = function() {
        var i , j;
        this.srr = new Array();
        this.vis = new Array();
        this.arr = new Array();
        this.brr = new Array();
        this.memo = new Array();
        this.done = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.srr.push( "" );
            this.vis.push( 0 );
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.memo.push( new Array() );
            this.done.push( new Array() );
            for( j = 0 ; j < this.lim1 ; j++ ) {
                this.memo[ i ].push( -1 );
                this.done[ i ].push( 0 );
            }
        }
    };

    this.init = function() {
        this.lim1 = 2010;
        this.lim2 = 2;
        this.lim3 = 2010;
        this.cc = 1;
        this.ind = 1;
        this.n = 0;
        this.cn = 0;
        this.declareAndFillArrays();
    };

    this.memsetArray1D = function( arrParam , val ) {
        var i;
        if( arrParam == null ) {
            throw new Error( "No array supplied in the parameter!" );
        }
        if( val == null ) {
            throw new Error( "No value for memset has been supplied in the parameter!" );
        }
        arrParam = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            arrParam.push( val );
        }
        return arrParam;
    };

    this.getStringLength = function( stringData ) {
        var len , lengthType;
        len = stringData.length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = stringData.length();
        }
        else {
            len = stringData.length;
        }
        return len;
    };

    this.init();
}

function InputReader() {
    this.allLines = new Array();
    this.currrentLineNumber = 0;
    this.currrentCharacterIndex = 0;

    this.readAllLines = function() {
        var singleLine;
        while( true ) {
            try {
                singleLine = readline();
                if( singleLine == null ) {
                    break;
                }
            }
            catch( ex ) {
                break;
            }
            this.allLines.push( singleLine );
        }
    };

    this.readAllLinesFromRhinoStdin = function() {
        importPackage( java.io );
        importPackage( java.lang );
        var singleLine , reader;
        reader = new BufferedReader( new InputStreamReader( System[ "in" ] ) );
        this.allLines = [];
        while( true ) {
            singleLine = reader.readLine();
            if( singleLine != null ) {
                this.allLines.push( singleLine );
            }
            else {
                break;
            }
        }
    };

    this.readAllLinesFromNodeStdin = function() {
        var fsObj , size , rawData;
        process.stdin.setEncoding( 'ascii' );
        fsObj = require( 'fs' );
        size = fsObj.fstatSync( process.stdin.fd ).size;
        rawData = fsObj.readSync( process.stdin.fd , size )[ 0 ];
        this.parseRawData( rawData );
    };

    this.parseRawData = function( data ) {
        var len , i , currentString;
        len = data.length;
        currentString = "";
        for( i = 0 ; i < len ; i++ ) {
            if( data[ i ] == '\r' ) {
            }
            else if( data[ i ] == '\n' ) {
                this.allLines.push( currentString );
                currentString = "";
            }
            else {
                currentString += data[ i ];
            }
        }
        if( currentString != "" ) {
            this.allLines.push( currentString );
        }
    };

    this.readAllLinesFromFile = function( inputFileName ) {
        var currentDirectory , fsObj , inputFilePath , rawData;
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        inputFilePath = currentDirectory + "\\" + inputFileName;
        rawData = fsObj.readFileSync( inputFilePath , "utf8" );
        this.parseRawData( rawData );
    };

    this.next = function( flag ) {
        var len , i , startIdx , res , endIdx , lengthType;
        len = this.allLines[ this.currrentLineNumber ].length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = this.allLines[ this.currrentLineNumber ].length();
        }
        if( flag == 0 ) {
            res = "";
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            this.currrentLineNumber++;
            this.currrentCharacterIndex = 0;
            return res;
        }
        while( true ) {
            if( this.currrentLineNumber >= this.allLines.length ) {
                throw new Error( "No more tokens available!" );
            }
            startIdx = -1;
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != ' '.charCodeAt( 0 ) && this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != '\t'.charCodeAt( 0 ) ) {
                    startIdx = i;
                    break;
                }
            }
            if( startIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
                continue;
            }
            res = "";
            endIdx = -1;
            for( i = startIdx ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == ' '.charCodeAt( 0 ) || this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == '\t'.charCodeAt( 0 ) ) {
                    endIdx = i;
                    break;
                }
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            if( endIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
            }
            else {
                this.currrentCharacterIndex = endIdx;
            }
            return res;
        }
    };

    this.nextInt = function() {
        return parseInt( this.next( 1 ) );
    };

    this.nextDouble = function() {
        return parseFloat( this.next( 1 ) );
    };

    this.nextString = function() {
        return this.next( 1 );
    };

    this.nextLine = function() {
        this.next( 0 );
    };
}

function FileOutputHandler() {
    this.resultantStringArray = new Array();

    this.addNewLine = function( newString ) {
        this.resultantStringArray.push( newString );
    };

    this.clearPercase = function() {
        this.resultantStringArray = new Array();
    };

    this.flushOutOutputToFile = function( outputFileName ) {
        var i , sz , res , currentDirectory , fsObj , outputFilePath;
        res = "";
        sz = this.resultantStringArray.length;
        for( i = 0 ; i < sz ; i++ ) {
            if( i != 0 ) {
                res += "\n";
            }
            res += this.resultantStringArray[ i ];
        }
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        outputFilePath = currentDirectory + "\\" + outputFileName;
        if( currentDirectory.charAt( 1 ) != ":" ) {
            //not local machine/windows
            outputFilePath = outputFileName;
        }
        fsObj.writeFileSync( outputFilePath , res );
        this.clearPercase();
    };
}

function CodeExecutioner() {
    this.irObj = new InputReader();
    this.psObj = new ProblemSolver();
    this.fohObj = new FileOutputHandler();

    this.runCode = function() {
        var testCases , i , hasMoreTestCases , isLocalMachine , localContext;
        isLocalMachine = false;
        try {
            if( __dirname != null && __dirname.charAt( 1 ) == ':' ) {
                //only on windows
                isLocalMachine = true;
            }
        }
        catch( ex ) {
            isLocalMachine = false;
        }
        if( isLocalMachine == true ) {
            //local machine runs on node and relies on file i/o
            print = console.log;
            if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
                localContext = this.fohObj;
                print = function() {
                    localContext.addNewLine.apply( localContext , arguments );
                }
            }
            this.irObj.readAllLinesFromFile( this.psObj.INPUT_FILE_NAME );
        }
        else {
            //server machine
            try {
                var rlObj = readline;
                //server runs on javasctipt v8 distribution and has readline method on global context
                this.irObj.readAllLines();
            }
            catch( ex ) {
                try {
                    var pObj = process;
                    //server runs on node
                    print = console.log;
                    this.irObj.readAllLinesFromNodeStdin();
                }
                catch( ex ) {
                    try {
                        var ipObj = importPackage;
                        //server runs on rhino
                        this.irObj.readAllLinesFromRhinoStdin();
                    }
                    catch( ex ) {
                        throw new Error( "Unknown javasctipt distribution!" );
                    }
                }
            }
        }
        if( this.psObj.HAS_TEST_CASES == true ) {
            testCases = this.irObj.nextInt();
            for( i = 0 ; i < testCases ; i++ ) {
                this.psObj.clearPerCase();
                this.psObj.getInput( this.irObj );
                this.psObj.solveCase();
            }
        }
        else {
            while( true ) {
                this.psObj.clearPerCase();
                hasMoreTestCases = this.psObj.getInput( this.irObj );
                if( hasMoreTestCases == false ) {
                    break;
                }
                this.psObj.solveCase();
            }
        }
        if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
            //only works for local machine(tested)
            this.fohObj.flushOutOutputToFile( this.psObj.OUTPUT_FILE_NAME );
        }
    };

    this.runCode();
}

new CodeExecutioner();

var nums = readline().split(' ');
var n = parseInt(nums[0]);
var k = parseInt(nums[1]);
var a_in = readline().split(' ');
var a = new Array();

for(var i=0;i<a_in.length;i++)
{
    a[i] = parseInt(a_in[i]);
}

a.sort(sortNum);
var x = 0;
var ans = 0;
while(x<n)
{
    ans+=(a[x]-1)*2;
	x+=k;
}
print(ans);

function sortNum(a, b)
{
    return b-a;
}

function ProblemSolver() {

    this.dp = function( i , hand ) {
        var res , r1 , ret , a , b , c , d , j;
        if( i < 2 ) {
            return 0;
        }
        if( hand > this.lim1 ) {
            res = ( 1 << 23 );
            return res;
        }
        ret = this.done[ i ][ hand ];
        res = this.memo[ i ][ hand ];
        if( ret == this.cc ) {
            return res;
        }
        this.done[ i ][ hand ] = this.cc;
        if( this.arr[ i ] == 0 ) {
            res = this.dp( i - 1 , hand );
            this.memo[ i ][ hand ] = res;
            return res;
        }
        res = ( 1 << 23 );
        a = this.arr[ i ];
        b = Math.floor( a / this.k );
        c = a - ( b * this.k );
        if( c != 0 ) {
            if( hand >= c ) {
                d = 2 * ( i - 1 ) * b;
                r1 = this.dp( i - 1 , hand - c ) + d;
                res = Math.min( res , r1 );
            }
            else {
                b++;
                d = 2 * ( i - 1 ) * b;
                c = c - hand;
                r1 = this.dp( i - 1 , this.k - c ) + d;
                res = Math.min( res , r1 );
            }
        }
        else {
            d = 2 * ( i - 1 ) * b;
            r1 = this.dp( i - 1 , hand ) + d;
            res = Math.min( res , r1 );
        }
        this.memo[ i ][ hand ] = res;
        return res;
    };

    this.solveCasedp = function() {
        var res , i , j , a , b , c , d , e , hand , ma , prev , cur , inf;
        res = 0;
        inf = ( 1 << 23 );
        ma = -1;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a;
            }
        }
        res = this.dp( ma , 0 );
        print( res );
    };

    this.solveCase = function() {
        var res , i , j , a , b , c , d , e , hand , ma;
        res = 0;
        ma = -1;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a;
            }
        }
        hand = 0;
        for( i = ma ; i >= 2 ; i-- ) {
            if( this.arr[ i ] == 0 ) {
                continue;
            }
            if( hand < this.arr[ i ] ) {
                this.arr[ i ] -= hand;
                hand = 0;
            }
            else {
                hand -= this.arr[ i ];
                continue;
            }
            a = this.arr[ i ];
            b = Math.floor( a / this.k );
            c = b * ( i - 1 ) * 2;
            res += c;
            d = this.arr[ i ] - ( b * this.k );
            if( d > 0 ) {
                c = 1 * ( i - 1 ) * 2;
                d = ( this.k - d )
                res += c;
            }
            hand += d;
        }
        print( res );
    };

    this.getInput = function( irObj ) {
        var hasMoreInput , i;
        hasMoreInput = true;
        try {
            this.n = irObj.nextInt();
            this.k = irObj.nextInt();
            for( i = 0 ; i < this.n ; i++ ) {
                this.brr[ i ] = irObj.nextInt();
            }
        }
        catch( ex ) {
            hasMoreInput = false;
        }
        return hasMoreInput;
    };

    this.clearArraysPerCase = function() {
        var i , j;
        this.arr = new Array();
        this.brr = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
    };

    this.clearPerCase = function() {
        this.cn = 0;
        this.cc++;
        this.clearArraysPerCase();
    };

    this.HAS_TEST_CASES = false;
    this.INPUT_FILE_NAME = "test.in";
    this.OUTPUT_FILE_NAME = "out.txt";
    this.DO_OUTPUT_TO_FILE = false;

    this.declareAndFillArrays = function() {
        var i , j;
        this.srr = new Array();
        this.vis = new Array();
        this.arr = new Array();
        this.brr = new Array();
        this.memo = new Array();
        this.done = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.srr.push( "" );
            this.vis.push( 0 );
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.memo.push( new Array() );
            this.done.push( new Array() );
            for( j = 0 ; j < this.lim1 ; j++ ) {
                this.memo[ i ].push( -1 );
                this.done[ i ].push( 0 );
            }
        }
    };

    this.init = function() {
        this.lim1 = 2010;
        this.lim2 = 2;
        this.lim3 = 2010;
        this.cc = 1;
        this.ind = 1;
        this.n = 0;
        this.cn = 0;
        this.declareAndFillArrays();
    };

    this.memsetArray1D = function( arrParam , val ) {
        var i;
        if( arrParam == null ) {
            throw new Error( "No array supplied in the parameter!" );
        }
        if( val == null ) {
            throw new Error( "No value for memset has been supplied in the parameter!" );
        }
        arrParam = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            arrParam.push( val );
        }
        return arrParam;
    };

    this.getStringLength = function( stringData ) {
        var len , lengthType;
        len = stringData.length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = stringData.length();
        }
        else {
            len = stringData.length;
        }
        return len;
    };

    this.init();
}

function InputReader() {
    this.allLines = new Array();
    this.currrentLineNumber = 0;
    this.currrentCharacterIndex = 0;

    this.readAllLines = function() {
        var singleLine;
        while( true ) {
            try {
                singleLine = readline();
                if( singleLine == null ) {
                    break;
                }
            }
            catch( ex ) {
                break;
            }
            this.allLines.push( singleLine );
        }
    };

    this.readAllLinesFromRhinoStdin = function() {
        importPackage( java.io );
        importPackage( java.lang );
        var singleLine , reader;
        reader = new BufferedReader( new InputStreamReader( System[ "in" ] ) );
        this.allLines = [];
        while( true ) {
            singleLine = reader.readLine();
            if( singleLine != null ) {
                this.allLines.push( singleLine );
            }
            else {
                break;
            }
        }
    };

    this.readAllLinesFromNodeStdin = function() {
        var fsObj , size , rawData;
        process.stdin.setEncoding( 'ascii' );
        fsObj = require( 'fs' );
        size = fsObj.fstatSync( process.stdin.fd ).size;
        rawData = fsObj.readSync( process.stdin.fd , size )[ 0 ];
        this.parseRawData( rawData );
    };

    this.parseRawData = function( data ) {
        var len , i , currentString;
        len = data.length;
        currentString = "";
        for( i = 0 ; i < len ; i++ ) {
            if( data[ i ] == '\r' ) {
            }
            else if( data[ i ] == '\n' ) {
                this.allLines.push( currentString );
                currentString = "";
            }
            else {
                currentString += data[ i ];
            }
        }
        if( currentString != "" ) {
            this.allLines.push( currentString );
        }
    };

    this.readAllLinesFromFile = function( inputFileName ) {
        var currentDirectory , fsObj , inputFilePath , rawData;
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        inputFilePath = currentDirectory + "\\" + inputFileName;
        rawData = fsObj.readFileSync( inputFilePath , "utf8" );
        this.parseRawData( rawData );
    };

    this.next = function( flag ) {
        var len , i , startIdx , res , endIdx , lengthType;
        len = this.allLines[ this.currrentLineNumber ].length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = this.allLines[ this.currrentLineNumber ].length();
        }
        if( flag == 0 ) {
            res = "";
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            this.currrentLineNumber++;
            this.currrentCharacterIndex = 0;
            return res;
        }
        while( true ) {
            if( this.currrentLineNumber >= this.allLines.length ) {
                throw new Error( "No more tokens available!" );
            }
            startIdx = -1;
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != ' '.charCodeAt( 0 ) && this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != '\t'.charCodeAt( 0 ) ) {
                    startIdx = i;
                    break;
                }
            }
            if( startIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
                continue;
            }
            res = "";
            endIdx = -1;
            for( i = startIdx ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == ' '.charCodeAt( 0 ) || this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == '\t'.charCodeAt( 0 ) ) {
                    endIdx = i;
                    break;
                }
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            if( endIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
            }
            else {
                this.currrentCharacterIndex = endIdx;
            }
            return res;
        }
    };

    this.nextInt = function() {
        return parseInt( this.next( 1 ) );
    };

    this.nextDouble = function() {
        return parseFloat( this.next( 1 ) );
    };

    this.nextString = function() {
        return this.next( 1 );
    };

    this.nextLine = function() {
        this.next( 0 );
    };
}

function FileOutputHandler() {
    this.resultantStringArray = new Array();

    this.addNewLine = function( newString ) {
        this.resultantStringArray.push( newString );
    };

    this.clearPercase = function() {
        this.resultantStringArray = new Array();
    };

    this.flushOutOutputToFile = function( outputFileName ) {
        var i , sz , res , currentDirectory , fsObj , outputFilePath;
        res = "";
        sz = this.resultantStringArray.length;
        for( i = 0 ; i < sz ; i++ ) {
            if( i != 0 ) {
                res += "\n";
            }
            res += this.resultantStringArray[ i ];
        }
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        outputFilePath = currentDirectory + "\\" + outputFileName;
        if( currentDirectory.charAt( 1 ) != ":" ) {
            //not local machine/windows
            outputFilePath = outputFileName;
        }
        fsObj.writeFileSync( outputFilePath , res );
        this.clearPercase();
    };
}

function CodeExecutioner() {
    this.irObj = new InputReader();
    this.psObj = new ProblemSolver();
    this.fohObj = new FileOutputHandler();

    this.runCode = function() {
        var testCases , i , hasMoreTestCases , isLocalMachine , localContext;
        isLocalMachine = false;
        try {
            if( __dirname != null && __dirname.charAt( 1 ) == ':' ) {
                //only on windows
                isLocalMachine = true;
            }
        }
        catch( ex ) {
            isLocalMachine = false;
        }
        if( isLocalMachine == true ) {
            //local machine runs on node and relies on file i/o
            print = console.log;
            if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
                localContext = this.fohObj;
                print = function() {
                    localContext.addNewLine.apply( localContext , arguments );
                }
            }
            this.irObj.readAllLinesFromFile( this.psObj.INPUT_FILE_NAME );
        }
        else {
            //server machine
            try {
                var rlObj = readline;
                //server runs on javasctipt v8 distribution and has readline method on global context
                this.irObj.readAllLines();
            }
            catch( ex ) {
                try {
                    var pObj = process;
                    //server runs on node
                    print = console.log;
                    this.irObj.readAllLinesFromNodeStdin();
                }
                catch( ex ) {
                    try {
                        var ipObj = importPackage;
                        //server runs on rhino
                        this.irObj.readAllLinesFromRhinoStdin();
                    }
                    catch( ex ) {
                        throw new Error( "Unknown javasctipt distribution!" );
                    }
                }
            }
        }
        if( this.psObj.HAS_TEST_CASES == true ) {
            testCases = this.irObj.nextInt();
            for( i = 0 ; i < testCases ; i++ ) {
                this.psObj.clearPerCase();
                this.psObj.getInput( this.irObj );
                this.psObj.solveCase();
            }
        }
        else {
            while( true ) {
                this.psObj.clearPerCase();
                hasMoreTestCases = this.psObj.getInput( this.irObj );
                if( hasMoreTestCases == false ) {
                    break;
                }
                this.psObj.solveCase();
            }
        }
        if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
            //only works for local machine(tested)
            this.fohObj.flushOutOutputToFile( this.psObj.OUTPUT_FILE_NAME );
        }
    };

    this.runCode();
}

new CodeExecutioner();

function ProblemSolver() {

    this.dp = function( i , hand ) {
        var res , r1 , ret , a , b , c , d , j;
        if( i < 2 ) {
            return 0;
        }
        if( hand > this.lim1 ) {
            res = ( 1 << 23 );
            return res;
        }
        ret = this.done[ i ][ hand ];
        res = this.memo[ i ][ hand ];
        if( ret == this.cc ) {
            return res;
        }
        this.done[ i ][ hand ] = this.cc;
        if( this.arr[ i ] == 0 ) {
            res = this.dp( i - 1 , hand );
            this.memo[ i ][ hand ] = res;
            return res;
        }
        res = ( 1 << 23 );
        a = this.arr[ i ];
        b = Math.floor( a / this.k );
        c = a - ( b * this.k );
        if( c != 0 ) {
            if( hand >= c ) {
                d = 2 * ( i - 1 ) * b;
                r1 = this.dp( i - 1 , hand - c ) + d;
                res = Math.min( res , r1 );
            }
            else {
                b++;
                d = 2 * ( i - 1 ) * b;
                c = c - hand;
                r1 = this.dp( i - 1 , this.k - c ) + d;
                res = Math.min( res , r1 );
            }
        }
        else {
            d = 2 * ( i - 1 ) * b;
            r1 = this.dp( i - 1 , hand ) + d;
            res = Math.min( res , r1 );
        }
        this.memo[ i ][ hand ] = res;
        return res;
    };

    this.solveCase = function() {
        var res , i , j , a , b , c , d , e , hand , ma , prev , cur , inf;
        res = 0;
        inf = ( 1 << 23 );
        ma = -1;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a;
            }
        }
        res = this.dp( ma , 0 );
        print( res );
    };

    this.solveCaseGreedy = function() {
        var res , i , j , a , b , c , d , e , hand , ma;
        res = 0;
        ma = -1;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a;
            }
        }
        hand = 0;
        for( i = ma ; i >= 2 ; i-- ) {
            if( this.arr[ i ] == 0 ) {
                continue;
            }
            if( hand < this.arr[ i ] ) {
                this.arr[ i ] -= hand;
                hand = 0;
            }
            else {
                hand -= this.arr[ i ];
                continue;
            }
            a = this.arr[ i ];
            b = Math.floor( a / this.k );
            c = b * ( i - 1 ) * 2;
            res += c;
            d = this.arr[ i ] - ( b * this.k );
            if( d > 0 ) {
                c = 1 * ( i - 1 ) * 2;
                res += c;
            }
            hand += d;
        }
        print( res );
    };

    this.getInput = function( irObj ) {
        var hasMoreInput , i;
        hasMoreInput = true;
        try {
            this.n = irObj.nextInt();
            this.k = irObj.nextInt();
            for( i = 0 ; i < this.n ; i++ ) {
                this.brr[ i ] = irObj.nextInt();
            }
        }
        catch( ex ) {
            hasMoreInput = false;
        }
        return hasMoreInput;
    };

    this.clearArraysPerCase = function() {
        var i , j;
        this.arr = new Array();
        this.brr = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
    };

    this.clearPerCase = function() {
        this.cn = 0;
        this.cc++;
        this.clearArraysPerCase();
    };

    this.HAS_TEST_CASES = false;
    this.INPUT_FILE_NAME = "test.in";
    this.OUTPUT_FILE_NAME = "out.txt";
    this.DO_OUTPUT_TO_FILE = false;

    this.declareAndFillArrays = function() {
        var i , j;
        this.srr = new Array();
        this.vis = new Array();
        this.arr = new Array();
        this.brr = new Array();
        this.memo = new Array();
        this.done = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.srr.push( "" );
            this.vis.push( 0 );
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.memo.push( new Array() );
            this.done.push( new Array() );
            for( j = 0 ; j < this.lim1 ; j++ ) {
                this.memo[ i ].push( -1 );
                this.done[ i ].push( 0 );
            }
        }
    };

    this.init = function() {
        this.lim1 = 2010;
        this.lim2 = 2;
        this.lim3 = 2010;
        this.cc = 1;
        this.ind = 1;
        this.n = 0;
        this.cn = 0;
        this.declareAndFillArrays();
    };

    this.memsetArray1D = function( arrParam , val ) {
        var i;
        if( arrParam == null ) {
            throw new Error( "No array supplied in the parameter!" );
        }
        if( val == null ) {
            throw new Error( "No value for memset has been supplied in the parameter!" );
        }
        arrParam = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            arrParam.push( val );
        }
        return arrParam;
    };

    this.getStringLength = function( stringData ) {
        var len , lengthType;
        len = stringData.length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = stringData.length();
        }
        else {
            len = stringData.length;
        }
        return len;
    };

    this.init();
}

function InputReader() {
    this.allLines = new Array();
    this.currrentLineNumber = 0;
    this.currrentCharacterIndex = 0;

    this.readAllLines = function() {
        var singleLine;
        while( true ) {
            try {
                singleLine = readline();
                if( singleLine == null ) {
                    break;
                }
            }
            catch( ex ) {
                break;
            }
            this.allLines.push( singleLine );
        }
    };

    this.readAllLinesFromRhinoStdin = function() {
        importPackage( java.io );
        importPackage( java.lang );
        var singleLine , reader;
        reader = new BufferedReader( new InputStreamReader( System[ "in" ] ) );
        this.allLines = [];
        while( true ) {
            singleLine = reader.readLine();
            if( singleLine != null ) {
                this.allLines.push( singleLine );
            }
            else {
                break;
            }
        }
    };

    this.readAllLinesFromNodeStdin = function() {
        var fsObj , size , rawData;
        process.stdin.setEncoding( 'ascii' );
        fsObj = require( 'fs' );
        size = fsObj.fstatSync( process.stdin.fd ).size;
        rawData = fsObj.readSync( process.stdin.fd , size )[ 0 ];
        this.parseRawData( rawData );
    };

    this.parseRawData = function( data ) {
        var len , i , currentString;
        len = data.length;
        currentString = "";
        for( i = 0 ; i < len ; i++ ) {
            if( data[ i ] == '\r' ) {
            }
            else if( data[ i ] == '\n' ) {
                this.allLines.push( currentString );
                currentString = "";
            }
            else {
                currentString += data[ i ];
            }
        }
        if( currentString != "" ) {
            this.allLines.push( currentString );
        }
    };

    this.readAllLinesFromFile = function( inputFileName ) {
        var currentDirectory , fsObj , inputFilePath , rawData;
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        inputFilePath = currentDirectory + "\\" + inputFileName;
        rawData = fsObj.readFileSync( inputFilePath , "utf8" );
        this.parseRawData( rawData );
    };

    this.next = function( flag ) {
        var len , i , startIdx , res , endIdx , lengthType;
        len = this.allLines[ this.currrentLineNumber ].length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = this.allLines[ this.currrentLineNumber ].length();
        }
        if( flag == 0 ) {
            res = "";
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            this.currrentLineNumber++;
            this.currrentCharacterIndex = 0;
            return res;
        }
        while( true ) {
            if( this.currrentLineNumber >= this.allLines.length ) {
                throw new Error( "No more tokens available!" );
            }
            startIdx = -1;
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != ' '.charCodeAt( 0 ) && this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != '\t'.charCodeAt( 0 ) ) {
                    startIdx = i;
                    break;
                }
            }
            if( startIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
                continue;
            }
            res = "";
            endIdx = -1;
            for( i = startIdx ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == ' '.charCodeAt( 0 ) || this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == '\t'.charCodeAt( 0 ) ) {
                    endIdx = i;
                    break;
                }
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            if( endIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
            }
            else {
                this.currrentCharacterIndex = endIdx;
            }
            return res;
        }
    };

    this.nextInt = function() {
        return parseInt( this.next( 1 ) );
    };

    this.nextDouble = function() {
        return parseFloat( this.next( 1 ) );
    };

    this.nextString = function() {
        return this.next( 1 );
    };

    this.nextLine = function() {
        this.next( 0 );
    };
}

function FileOutputHandler() {
    this.resultantStringArray = new Array();

    this.addNewLine = function( newString ) {
        this.resultantStringArray.push( newString );
    };

    this.clearPercase = function() {
        this.resultantStringArray = new Array();
    };

    this.flushOutOutputToFile = function( outputFileName ) {
        var i , sz , res , currentDirectory , fsObj , outputFilePath;
        res = "";
        sz = this.resultantStringArray.length;
        for( i = 0 ; i < sz ; i++ ) {
            if( i != 0 ) {
                res += "\n";
            }
            res += this.resultantStringArray[ i ];
        }
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        outputFilePath = currentDirectory + "\\" + outputFileName;
        if( currentDirectory.charAt( 1 ) != ":" ) {
            //not local machine/windows
            outputFilePath = outputFileName;
        }
        fsObj.writeFileSync( outputFilePath , res );
        this.clearPercase();
    };
}

function CodeExecutioner() {
    this.irObj = new InputReader();
    this.psObj = new ProblemSolver();
    this.fohObj = new FileOutputHandler();

    this.runCode = function() {
        var testCases , i , hasMoreTestCases , isLocalMachine , localContext;
        isLocalMachine = false;
        try {
            if( __dirname != null && __dirname.charAt( 1 ) == ':' ) {
                //only on windows
                isLocalMachine = true;
            }
        }
        catch( ex ) {
            isLocalMachine = false;
        }
        if( isLocalMachine == true ) {
            //local machine runs on node and relies on file i/o
            print = console.log;
            if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
                localContext = this.fohObj;
                print = function() {
                    localContext.addNewLine.apply( localContext , arguments );
                }
            }
            this.irObj.readAllLinesFromFile( this.psObj.INPUT_FILE_NAME );
        }
        else {
            //server machine
            try {
                var rlObj = readline;
                //server runs on javasctipt v8 distribution and has readline method on global context
                this.irObj.readAllLines();
            }
            catch( ex ) {
                try {
                    var pObj = process;
                    //server runs on node
                    print = console.log;
                    this.irObj.readAllLinesFromNodeStdin();
                }
                catch( ex ) {
                    try {
                        var ipObj = importPackage;
                        //server runs on rhino
                        this.irObj.readAllLinesFromRhinoStdin();
                    }
                    catch( ex ) {
                        throw new Error( "Unknown javasctipt distribution!" );
                    }
                }
            }
        }
        if( this.psObj.HAS_TEST_CASES == true ) {
            testCases = this.irObj.nextInt();
            for( i = 0 ; i < testCases ; i++ ) {
                this.psObj.clearPerCase();
                this.psObj.getInput( this.irObj );
                this.psObj.solveCase();
            }
        }
        else {
            while( true ) {
                this.psObj.clearPerCase();
                hasMoreTestCases = this.psObj.getInput( this.irObj );
                if( hasMoreTestCases == false ) {
                    break;
                }
                this.psObj.solveCase();
            }
        }
        if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
            //only works for local machine(tested)
            this.fohObj.flushOutOutputToFile( this.psObj.OUTPUT_FILE_NAME );
        }
    };

    this.runCode();
}

new CodeExecutioner();

var str1 = readline().split(" ");
var f = readline().split(" ");
var n = str1[0];
var k = str1[1];
var x = 0;
var f1 = [];
for (j in f) f1[j] = f [j];
f1.sort(mySort);
for (i=f1.length-1;i>-1;i=i-k){
    x = x + ((f1[i]-1)*2);
}
print(x);
function mySort(a,b) {return (a-b);}

function main() {
  var t = readline().split(' ').map(x => +x), n = t[0], k = t[1];
  var a = readline().split(' ').map(x => +x);
  a.sort((u, v) => v - u);
  var ans = 0;
  for (var i = 0; i < n; i += k) {
    ans += (a[i] - 1) * 2;
  }
  print(ans);
}

if (typeof readline == 'undefined') {
  process.stdin.resume();
  process.stdin.setEncoding('ascii');

  var input_stdin = "";
  process.stdin.on('data', function (data) { input_stdin += data; });
  process.stdin.on('end', function () {
    // input_stdin = input_stdin.split(/\s/);
    input_stdin = input_stdin.split('\n');
    var curline = 0;
    readline = () => input_stdin[curline++];
    if (typeof print == 'undefined') print = console.log;
    main();
  });
} else main();

var input = readline().split(" "), n = +input[0], k = +input[1],
f = readline().split(" ").map(Number).sort(function(x,y){return y-x});
var x, cnt = 0;

for(; ;){
	if(f[0] == undefined){
		break;
	}
	x = f[0];
	f.splice(0,k);

	cnt += (x-1)*2;
}

write(cnt);

// 472B    Уроки дизайна задач: учимся у жизни

//var n = parseInt(readline());

// var input_line = readline().split(' ').map(Number);
var arr = readline().split(' ').map(Number);
var n = arr[0];
var k = arr[1];

var arr = readline().split(' ').map(Number);
arr.sort(function(a,b){return a-b;});
arr.reverse();

var out = 0;
var num = 0;
var sum_lift;
while (num < n) {
    out += (arr[num] - 1) * 2;

    if ((n - num) > k) {
        sum_lift = k;
        num += k;
    } else {
        sum_lift = n - num;
        num += n - num;
    };
}

print(out);

;(function () {

	print(function (n, k, f) {

		var sumTime = 0, _f = [];

		while (n > 0) {
			var peopleInLift = n >= k ? k : n,
				people = f.splice(0, peopleInLift),
				maxFloor = Math.max.apply(null, people);

			n -= peopleInLift;
			sumTime += 2 * maxFloor;
		}

		return sumTime;

	}.apply(null, readline().split(' ')
			.map(Number)
			.concat([
				readline().split(' ')
					.map(function (e) {
						return +e - 1;
					}).sort(function (a, b) {
						return b - a;
					})
			])
	));

}.call(this));

var inp,n,k,arr;

inp=readline().split(" ");
n=+inp[0];
k=+inp[1];
arr=readline().split(" ").map(function(a){return +a;});

var ans=0;

arr.sort(function(a,b) {return b-a});
for(var i=0; i<n; i+=k) {
    var max=arr[i];
    for(var j=i; j<i+k&&j<n; j++)
        max=Math.max(max,arr[j]);
    ans+=2*(max-1);
}

print(ans);

var n = readline().split(/\s/).map(Number), k = n[1], n = n[0],
			floors = readline().split(/\s/).map(Number).sort(function(a, b)	{ return b - a; }),
			rstTime = 0;

		for(var i = 0; i < floors.length;)	{
			var dFloor = floors.slice(i, i + k),
				_rstTime = 0;

			dFloor.forEach(function(f, idx)	{
				if(idx == 0 || idx == dFloor.length - 1)	{
					rstTime += f - 1;
				}

				if(idx != 0)	{
					rstTime += dFloor[idx - 1] - f;
				}

				if(dFloor.length == 1)	{
					rstTime += f - 1;
				}
			});

			i += k;
		}

		print(rstTime);

function ProblemSolver() {

    this.solveCase = function() {
        var res , i , j , a , b , c , d , e , hand , ma;
        res = 0;
        ma = -1 ;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a ;
            }
        }
        for( i = ma ; i >= 1 ; i-- ) {
            if( this.arr[ i ] == 0 ) {
                continue;
            }
            if( i != ma ) {
                if( hand <= this.arr[ i ] ) {
                    this.arr[ i ] -= hand;
                    hand = 0 ;
                }
                else {
                    hand -= this.arr[ i ];
                    continue;
                }
            }
            if( i == 1 ) {
                break;
            }
            a = this.arr[ i ];
            b = Math.floor( a / this.k );
            c = b * ( i - 1 ) * 2;
            res += c;
            hand = this.arr[ i ] - ( b * this.k );
            if( hand > 0 ) {
                c = 1 * ( i - 1 ) * 2;
                res += c;
            }
        }
        print( res );
    };

    this.getInput = function( irObj ) {
        var hasMoreInput , i;
        hasMoreInput = true;
        try {
            this.n = irObj.nextInt();
            this.k = irObj.nextInt();
            for( i = 0 ; i < this.n ; i++ ) {
                this.brr[ i ] = irObj.nextInt() ;
            }
        }
        catch( ex ) {
            hasMoreInput = false;
        }
        return hasMoreInput;
    };

    this.clearArraysPerCase = function() {
        var i;
        this.arr = new Array();
        this.brr = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
    };

    this.clearPerCase = function() {
        this.cn = 0;
        this.cc++;
        this.clearArraysPerCase() ;
    };

    this.HAS_TEST_CASES = false;
    this.INPUT_FILE_NAME = "test.in";
    this.OUTPUT_FILE_NAME = "out.txt";
    this.DO_OUTPUT_TO_FILE = false;

    this.declareAndFillArrays = function() {
        var i , j;
        this.srr = new Array();
        this.vis = new Array();
        this.arr = new Array();
        this.brr = new Array();
        this.memo = new Array();
        this.done = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.srr.push( "" );
            this.vis.push( 0 );
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
        for( i = 0 ; i < this.lim2 ; i++ ) {
            this.memo.push( new Array() );
            this.done.push( new Array() );
            for( j = 0 ; j < this.lim2 ; j++ ) {
                this.memo[ i ].push( -1 );
                this.done[ i ].push( 0 );
            }
        }
    };

    this.init = function() {
        this.lim1 = 2010;
        this.lim2 = 110;
        this.cc = 1;
        this.ind = 1;
        this.n = 0;
        this.cn = 0;
        this.declareAndFillArrays();
    };

    this.memsetArray1D = function( arrParam , val ) {
        var i;
        if( arrParam == null ) {
            throw new Error( "No array supplied in the parameter!" );
        }
        if( val == null ) {
            throw new Error( "No value for memset has been supplied in the parameter!" );
        }
        arrParam = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            arrParam.push( val );
        }
        return arrParam;
    };

    this.getStringLength = function( stringData ) {
        var len , lengthType;
        len = stringData.length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = stringData.length();
        }
        else {
            len = stringData.length;
        }
        return len;
    };

    this.init();
}

function InputReader() {
    this.allLines = new Array();
    this.currrentLineNumber = 0;
    this.currrentCharacterIndex = 0;

    this.readAllLines = function() {
        var singleLine;
        while( true ) {
            try {
                singleLine = readline();
                if( singleLine == null ) {
                    break;
                }
            }
            catch( ex ) {
                break;
            }
            this.allLines.push( singleLine );
        }
    };

    this.readAllLinesFromRhinoStdin = function() {
        importPackage( java.io );
        importPackage( java.lang );
        var singleLine , reader;
        reader = new BufferedReader( new InputStreamReader( System[ "in" ] ) );
        this.allLines = [];
        while( true ) {
            singleLine = reader.readLine();
            if( singleLine != null ) {
                this.allLines.push( singleLine );
            }
            else {
                break;
            }
        }
    };

    this.readAllLinesFromNodeStdin = function() {
        var fsObj , size , rawData;
        process.stdin.setEncoding( 'ascii' );
        fsObj = require( 'fs' );
        size = fsObj.fstatSync( process.stdin.fd ).size;
        rawData = fsObj.readSync( process.stdin.fd , size )[ 0 ];
        this.parseRawData( rawData );
    };

    this.parseRawData = function( data ) {
        var len , i , currentString;
        len = data.length;
        currentString = "";
        for( i = 0 ; i < len ; i++ ) {
            if( data[ i ] == '\r' ) {
            }
            else if( data[ i ] == '\n' ) {
                this.allLines.push( currentString );
                currentString = "";
            }
            else {
                currentString += data[ i ];
            }
        }
        if( currentString != "" ) {
            this.allLines.push( currentString );
        }
    };

    this.readAllLinesFromFile = function( inputFileName ) {
        var currentDirectory , fsObj , inputFilePath , rawData;
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        inputFilePath = currentDirectory + "\\" + inputFileName;
        rawData = fsObj.readFileSync( inputFilePath , "utf8" );
        this.parseRawData( rawData );
    };

    this.next = function( flag ) {
        var len , i , startIdx , res , endIdx , lengthType;
        len = this.allLines[ this.currrentLineNumber ].length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = this.allLines[ this.currrentLineNumber ].length();
        }
        if( flag == 0 ) {
            res = "";
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            this.currrentLineNumber++;
            this.currrentCharacterIndex = 0;
            return res;
        }
        while( true ) {
            if( this.currrentLineNumber >= this.allLines.length ) {
                throw new Error( "No more tokens available!" );
            }
            startIdx = -1;
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != ' '.charCodeAt( 0 ) && this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != '\t'.charCodeAt( 0 ) ) {
                    startIdx = i;
                    break;
                }
            }
            if( startIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
                continue;
            }
            res = "";
            endIdx = -1;
            for( i = startIdx ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == ' '.charCodeAt( 0 ) || this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == '\t'.charCodeAt( 0 ) ) {
                    endIdx = i;
                    break;
                }
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            if( endIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
            }
            else {
                this.currrentCharacterIndex = endIdx;
            }
            return res;
        }
    };

    this.nextInt = function() {
        return parseInt( this.next( 1 ) );
    };

    this.nextDouble = function() {
        return parseFloat( this.next( 1 ) );
    };

    this.nextString = function() {
        return this.next( 1 );
    };

    this.nextLine = function() {
        this.next( 0 );
    };
}

function FileOutputHandler() {
    this.resultantStringArray = new Array();

    this.addNewLine = function( newString ) {
        this.resultantStringArray.push( newString );
    };

    this.clearPercase = function() {
        this.resultantStringArray = new Array();
    };

    this.flushOutOutputToFile = function( outputFileName ) {
        var i , sz , res , currentDirectory , fsObj , outputFilePath;
        res = "";
        sz = this.resultantStringArray.length;
        for( i = 0 ; i < sz ; i++ ) {
            if( i != 0 ) {
                res += "\n";
            }
            res += this.resultantStringArray[ i ];
        }
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        outputFilePath = currentDirectory + "\\" + outputFileName;
        if( currentDirectory.charAt( 1 ) != ":" ) {
            //not local machine/windows
            outputFilePath = outputFileName;
        }
        fsObj.writeFileSync( outputFilePath , res );
        this.clearPercase();
    };
}

function CodeExecutioner() {
    this.irObj = new InputReader();
    this.psObj = new ProblemSolver();
    this.fohObj = new FileOutputHandler();

    this.runCode = function() {
        var testCases , i , hasMoreTestCases , isLocalMachine , localContext;
        isLocalMachine = false;
        try {
            if( __dirname != null && __dirname.charAt( 1 ) == ':' ) {
                //only on windows
                isLocalMachine = true;
            }
        }
        catch( ex ) {
            isLocalMachine = false;
        }
        if( isLocalMachine == true ) {
            //local machine runs on node and relies on file i/o
            print = console.log;
            if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
                localContext = this.fohObj;
                print = function() {
                    localContext.addNewLine.apply( localContext , arguments );
                }
            }
            this.irObj.readAllLinesFromFile( this.psObj.INPUT_FILE_NAME );
        }
        else {
            //server machine
            try {
                var rlObj = readline;
                //server runs on javasctipt v8 distribution and has readline method on global context
                this.irObj.readAllLines();
            }
            catch( ex ) {
                try {
                    var pObj = process;
                    //server runs on node
                    print = console.log;
                    this.irObj.readAllLinesFromNodeStdin();
                }
                catch( ex ) {
                    try {
                        var ipObj = importPackage;
                        //server runs on rhino
                        this.irObj.readAllLinesFromRhinoStdin();
                    }
                    catch( ex ) {
                        throw new Error( "Unknown javasctipt distribution!" );
                    }
                }
            }
        }
        if( this.psObj.HAS_TEST_CASES == true ) {
            testCases = this.irObj.nextInt();
            for( i = 0 ; i < testCases ; i++ ) {
                this.psObj.clearPerCase();
                this.psObj.getInput( this.irObj );
                this.psObj.solveCase();
            }
        }
        else {
            while( true ) {
                this.psObj.clearPerCase();
                hasMoreTestCases = this.psObj.getInput( this.irObj );
                if( hasMoreTestCases == false ) {
                    break;
                }
                this.psObj.solveCase();
            }
        }
        if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
            //only works for local machine(tested)
            this.fohObj.flushOutOutputToFile( this.psObj.OUTPUT_FILE_NAME );
        }
    };

    this.runCode();
}

new CodeExecutioner();

function ProblemSolver() {

    this.solveCase = function() {
        var res , i , j , a , b , c , d , e , hand , ma;
        res = 0;
        ma = -1 ;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a ;
            }
        }
        for( i = ma ; i >= 0 ; i-- ) {
            if( i != ma ) {
                if( hand <= this.arr[ i ] ) {
                    this.arr[ i ] -= hand;
                    hand = 0 ;
                }
                else {
                    hand -= this.arr[ i ];
                    continue;
                }
            }
            a = this.arr[ i ];
            b = Math.floor( a / this.k );
            c = b * ( i - 1 ) * 2;
            res += c;
            hand = this.arr[ i ] - ( b * this.k );
            if( hand > 0 ) {
                c = 1 * ( i - 1 ) * 2;
                res += c;
            }
        }
        print( res );
    };

    this.getInput = function( irObj ) {
        var hasMoreInput , i;
        hasMoreInput = true;
        try {
            this.n = irObj.nextInt();
            this.k = irObj.nextInt();
            for( i = 0 ; i < this.n ; i++ ) {
                this.brr[ i ] = irObj.nextInt() ;
            }
        }
        catch( ex ) {
            hasMoreInput = false;
        }
        return hasMoreInput;
    };

    this.clearArraysPerCase = function() {
        var i;
        this.arr = new Array();
        this.brr = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
    };

    this.clearPerCase = function() {
        this.cn = 0;
        this.cc++;
        this.clearArraysPerCase() ;
    };

    this.HAS_TEST_CASES = false;
    this.INPUT_FILE_NAME = "test.in";
    this.OUTPUT_FILE_NAME = "out.txt";
    this.DO_OUTPUT_TO_FILE = false;

    this.declareAndFillArrays = function() {
        var i , j;
        this.srr = new Array();
        this.vis = new Array();
        this.arr = new Array();
        this.brr = new Array();
        this.memo = new Array();
        this.done = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.srr.push( "" );
            this.vis.push( 0 );
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
        for( i = 0 ; i < this.lim2 ; i++ ) {
            this.memo.push( new Array() );
            this.done.push( new Array() );
            for( j = 0 ; j < this.lim2 ; j++ ) {
                this.memo[ i ].push( -1 );
                this.done[ i ].push( 0 );
            }
        }
    };

    this.init = function() {
        this.lim1 = 2010;
        this.lim2 = 110;
        this.cc = 1;
        this.ind = 1;
        this.n = 0;
        this.cn = 0;
        this.declareAndFillArrays();
    };

    this.memsetArray1D = function( arrParam , val ) {
        var i;
        if( arrParam == null ) {
            throw new Error( "No array supplied in the parameter!" );
        }
        if( val == null ) {
            throw new Error( "No value for memset has been supplied in the parameter!" );
        }
        arrParam = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            arrParam.push( val );
        }
        return arrParam;
    };

    this.getStringLength = function( stringData ) {
        var len , lengthType;
        len = stringData.length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = stringData.length();
        }
        else {
            len = stringData.length;
        }
        return len;
    };

    this.init();
}

function InputReader() {
    this.allLines = new Array();
    this.currrentLineNumber = 0;
    this.currrentCharacterIndex = 0;

    this.readAllLines = function() {
        var singleLine;
        while( true ) {
            try {
                singleLine = readline();
                if( singleLine == null ) {
                    break;
                }
            }
            catch( ex ) {
                break;
            }
            this.allLines.push( singleLine );
        }
    };

    this.readAllLinesFromRhinoStdin = function() {
        importPackage( java.io );
        importPackage( java.lang );
        var singleLine , reader;
        reader = new BufferedReader( new InputStreamReader( System[ "in" ] ) );
        this.allLines = [];
        while( true ) {
            singleLine = reader.readLine();
            if( singleLine != null ) {
                this.allLines.push( singleLine );
            }
            else {
                break;
            }
        }
    };

    this.readAllLinesFromNodeStdin = function() {
        var fsObj , size , rawData;
        process.stdin.setEncoding( 'ascii' );
        fsObj = require( 'fs' );
        size = fsObj.fstatSync( process.stdin.fd ).size;
        rawData = fsObj.readSync( process.stdin.fd , size )[ 0 ];
        this.parseRawData( rawData );
    };

    this.parseRawData = function( data ) {
        var len , i , currentString;
        len = data.length;
        currentString = "";
        for( i = 0 ; i < len ; i++ ) {
            if( data[ i ] == '\r' ) {
            }
            else if( data[ i ] == '\n' ) {
                this.allLines.push( currentString );
                currentString = "";
            }
            else {
                currentString += data[ i ];
            }
        }
        if( currentString != "" ) {
            this.allLines.push( currentString );
        }
    };

    this.readAllLinesFromFile = function( inputFileName ) {
        var currentDirectory , fsObj , inputFilePath , rawData;
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        inputFilePath = currentDirectory + "\\" + inputFileName;
        rawData = fsObj.readFileSync( inputFilePath , "utf8" );
        this.parseRawData( rawData );
    };

    this.next = function( flag ) {
        var len , i , startIdx , res , endIdx , lengthType;
        len = this.allLines[ this.currrentLineNumber ].length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = this.allLines[ this.currrentLineNumber ].length();
        }
        if( flag == 0 ) {
            res = "";
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            this.currrentLineNumber++;
            this.currrentCharacterIndex = 0;
            return res;
        }
        while( true ) {
            if( this.currrentLineNumber >= this.allLines.length ) {
                throw new Error( "No more tokens available!" );
            }
            startIdx = -1;
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != ' '.charCodeAt( 0 ) && this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != '\t'.charCodeAt( 0 ) ) {
                    startIdx = i;
                    break;
                }
            }
            if( startIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
                continue;
            }
            res = "";
            endIdx = -1;
            for( i = startIdx ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == ' '.charCodeAt( 0 ) || this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == '\t'.charCodeAt( 0 ) ) {
                    endIdx = i;
                    break;
                }
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            if( endIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
            }
            else {
                this.currrentCharacterIndex = endIdx;
            }
            return res;
        }
    };

    this.nextInt = function() {
        return parseInt( this.next( 1 ) );
    };

    this.nextDouble = function() {
        return parseFloat( this.next( 1 ) );
    };

    this.nextString = function() {
        return this.next( 1 );
    };

    this.nextLine = function() {
        this.next( 0 );
    };
}

function FileOutputHandler() {
    this.resultantStringArray = new Array();

    this.addNewLine = function( newString ) {
        this.resultantStringArray.push( newString );
    };

    this.clearPercase = function() {
        this.resultantStringArray = new Array();
    };

    this.flushOutOutputToFile = function( outputFileName ) {
        var i , sz , res , currentDirectory , fsObj , outputFilePath;
        res = "";
        sz = this.resultantStringArray.length;
        for( i = 0 ; i < sz ; i++ ) {
            if( i != 0 ) {
                res += "\n";
            }
            res += this.resultantStringArray[ i ];
        }
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        outputFilePath = currentDirectory + "\\" + outputFileName;
        if( currentDirectory.charAt( 1 ) != ":" ) {
            //not local machine/windows
            outputFilePath = outputFileName;
        }
        fsObj.writeFileSync( outputFilePath , res );
        this.clearPercase();
    };
}

function CodeExecutioner() {
    this.irObj = new InputReader();
    this.psObj = new ProblemSolver();
    this.fohObj = new FileOutputHandler();

    this.runCode = function() {
        var testCases , i , hasMoreTestCases , isLocalMachine , localContext;
        isLocalMachine = false;
        try {
            if( __dirname != null && __dirname.charAt( 1 ) == ':' ) {
                //only on windows
                isLocalMachine = true;
            }
        }
        catch( ex ) {
            isLocalMachine = false;
        }
        if( isLocalMachine == true ) {
            //local machine runs on node and relies on file i/o
            print = console.log;
            if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
                localContext = this.fohObj;
                print = function() {
                    localContext.addNewLine.apply( localContext , arguments );
                }
            }
            this.irObj.readAllLinesFromFile( this.psObj.INPUT_FILE_NAME );
        }
        else {
            //server machine
            try {
                var rlObj = readline;
                //server runs on javasctipt v8 distribution and has readline method on global context
                this.irObj.readAllLines();
            }
            catch( ex ) {
                try {
                    var pObj = process;
                    //server runs on node
                    print = console.log;
                    this.irObj.readAllLinesFromNodeStdin();
                }
                catch( ex ) {
                    try {
                        var ipObj = importPackage;
                        //server runs on rhino
                        this.irObj.readAllLinesFromRhinoStdin();
                    }
                    catch( ex ) {
                        throw new Error( "Unknown javasctipt distribution!" );
                    }
                }
            }
        }
        if( this.psObj.HAS_TEST_CASES == true ) {
            testCases = this.irObj.nextInt();
            for( i = 0 ; i < testCases ; i++ ) {
                this.psObj.clearPerCase();
                this.psObj.getInput( this.irObj );
                this.psObj.solveCase();
            }
        }
        else {
            while( true ) {
                this.psObj.clearPerCase();
                hasMoreTestCases = this.psObj.getInput( this.irObj );
                if( hasMoreTestCases == false ) {
                    break;
                }
                this.psObj.solveCase();
            }
        }
        if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
            //only works for local machine(tested)
            this.fohObj.flushOutOutputToFile( this.psObj.OUTPUT_FILE_NAME );
        }
    };

    this.runCode();
}

new CodeExecutioner();

function ProblemSolver() {

    this.dp = function( i , hand ) {
        var res , r1 , ret , a , b , c , d , j;
        if( i < 2 ) {
            return 0;
        }
        if( hand > this.lim1 ) {
            res = ( 1 << 23 );
            return res;
        }
        ret = this.done[ i ][ hand ];
        res = this.memo[ i ][ hand ];
        if( ret == this.cc ) {
            return res;
        }
        this.done[ i ][ hand ] = this.cc;
        if( this.arr[ i ] == 0 ) {
            res = this.dp( i - 1 , hand );
            this.memo[ i ][ hand ] = res;
            return res;
        }
        res = ( 1 << 23 );
        a = this.arr[ i ];
        b = Math.floor( a / this.k );
        c = a - ( b * this.k );
        if( c != 0 ) {
            if( hand >= c ) {
                d = 2 * ( i - 1 ) * b;
                r1 = this.dp( i - 1 , hand - c ) + d;
                res = Math.min( res , r1 );
            }
            else {
                b++;
                d = 2 * ( i - 1 ) * b;
                c = c - hand;
                r1 = this.dp( i - 1 , this.k - c ) + d;
                res = Math.min( res , r1 );
            }
        }
        else {
            d = 2 * ( i - 1 ) * b;
            r1 = this.dp( i - 1 , hand ) + d;
            res = Math.min( res , r1 );
        }
        this.memo[ i ][ hand ] = res;
        return res;
    };

    this.solveCasedp = function() {
        var res , i , j , a , b , c , d , e , hand , ma , prev , cur , inf;
        res = 0;
        inf = ( 1 << 23 );
        ma = -1;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a;
            }
        }
        res = this.dp( ma , 0 );
        print( res );
    };

    this.solveCase = function() {
        var res , i , j , a , b , c , d , e , hand , ma;
        res = 0;
        ma = -1;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a;
            }
        }
        hand = 0;
        for( i = ma ; i >= 2 ; i-- ) {
            if( this.arr[ i ] == 0 ) {
                continue;
            }
            if( hand < this.arr[ i ] ) {
                this.arr[ i ] -= hand;
                hand = 0;
            }
            else {
                hand -= this.arr[ i ];
                continue;
            }
            a = this.arr[ i ];
            b = Math.floor( a / this.k );
            c = b * ( i - 1 ) * 2;
            res += c;
            d = this.arr[ i ] - ( b * this.k );
            if( d > 0 ) {
                c = 1 * ( i - 1 ) * 2;
                res += c;
            }
            hand += this.k - d;
        }
        print( res );
    };

    this.getInput = function( irObj ) {
        var hasMoreInput , i;
        hasMoreInput = true;
        try {
            this.n = irObj.nextInt();
            this.k = irObj.nextInt();
            for( i = 0 ; i < this.n ; i++ ) {
                this.brr[ i ] = irObj.nextInt();
            }
        }
        catch( ex ) {
            hasMoreInput = false;
        }
        return hasMoreInput;
    };

    this.clearArraysPerCase = function() {
        var i , j;
        this.arr = new Array();
        this.brr = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
    };

    this.clearPerCase = function() {
        this.cn = 0;
        this.cc++;
        this.clearArraysPerCase();
    };

    this.HAS_TEST_CASES = false;
    this.INPUT_FILE_NAME = "test.in";
    this.OUTPUT_FILE_NAME = "out.txt";
    this.DO_OUTPUT_TO_FILE = false;

    this.declareAndFillArrays = function() {
        var i , j;
        this.srr = new Array();
        this.vis = new Array();
        this.arr = new Array();
        this.brr = new Array();
        this.memo = new Array();
        this.done = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.srr.push( "" );
            this.vis.push( 0 );
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.memo.push( new Array() );
            this.done.push( new Array() );
            for( j = 0 ; j < this.lim1 ; j++ ) {
                this.memo[ i ].push( -1 );
                this.done[ i ].push( 0 );
            }
        }
    };

    this.init = function() {
        this.lim1 = 2010;
        this.lim2 = 2;
        this.lim3 = 2010;
        this.cc = 1;
        this.ind = 1;
        this.n = 0;
        this.cn = 0;
        this.declareAndFillArrays();
    };

    this.memsetArray1D = function( arrParam , val ) {
        var i;
        if( arrParam == null ) {
            throw new Error( "No array supplied in the parameter!" );
        }
        if( val == null ) {
            throw new Error( "No value for memset has been supplied in the parameter!" );
        }
        arrParam = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            arrParam.push( val );
        }
        return arrParam;
    };

    this.getStringLength = function( stringData ) {
        var len , lengthType;
        len = stringData.length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = stringData.length();
        }
        else {
            len = stringData.length;
        }
        return len;
    };

    this.init();
}

function InputReader() {
    this.allLines = new Array();
    this.currrentLineNumber = 0;
    this.currrentCharacterIndex = 0;

    this.readAllLines = function() {
        var singleLine;
        while( true ) {
            try {
                singleLine = readline();
                if( singleLine == null ) {
                    break;
                }
            }
            catch( ex ) {
                break;
            }
            this.allLines.push( singleLine );
        }
    };

    this.readAllLinesFromRhinoStdin = function() {
        importPackage( java.io );
        importPackage( java.lang );
        var singleLine , reader;
        reader = new BufferedReader( new InputStreamReader( System[ "in" ] ) );
        this.allLines = [];
        while( true ) {
            singleLine = reader.readLine();
            if( singleLine != null ) {
                this.allLines.push( singleLine );
            }
            else {
                break;
            }
        }
    };

    this.readAllLinesFromNodeStdin = function() {
        var fsObj , size , rawData;
        process.stdin.setEncoding( 'ascii' );
        fsObj = require( 'fs' );
        size = fsObj.fstatSync( process.stdin.fd ).size;
        rawData = fsObj.readSync( process.stdin.fd , size )[ 0 ];
        this.parseRawData( rawData );
    };

    this.parseRawData = function( data ) {
        var len , i , currentString;
        len = data.length;
        currentString = "";
        for( i = 0 ; i < len ; i++ ) {
            if( data[ i ] == '\r' ) {
            }
            else if( data[ i ] == '\n' ) {
                this.allLines.push( currentString );
                currentString = "";
            }
            else {
                currentString += data[ i ];
            }
        }
        if( currentString != "" ) {
            this.allLines.push( currentString );
        }
    };

    this.readAllLinesFromFile = function( inputFileName ) {
        var currentDirectory , fsObj , inputFilePath , rawData;
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        inputFilePath = currentDirectory + "\\" + inputFileName;
        rawData = fsObj.readFileSync( inputFilePath , "utf8" );
        this.parseRawData( rawData );
    };

    this.next = function( flag ) {
        var len , i , startIdx , res , endIdx , lengthType;
        len = this.allLines[ this.currrentLineNumber ].length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = this.allLines[ this.currrentLineNumber ].length();
        }
        if( flag == 0 ) {
            res = "";
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            this.currrentLineNumber++;
            this.currrentCharacterIndex = 0;
            return res;
        }
        while( true ) {
            if( this.currrentLineNumber >= this.allLines.length ) {
                throw new Error( "No more tokens available!" );
            }
            startIdx = -1;
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != ' '.charCodeAt( 0 ) && this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != '\t'.charCodeAt( 0 ) ) {
                    startIdx = i;
                    break;
                }
            }
            if( startIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
                continue;
            }
            res = "";
            endIdx = -1;
            for( i = startIdx ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == ' '.charCodeAt( 0 ) || this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == '\t'.charCodeAt( 0 ) ) {
                    endIdx = i;
                    break;
                }
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            if( endIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
            }
            else {
                this.currrentCharacterIndex = endIdx;
            }
            return res;
        }
    };

    this.nextInt = function() {
        return parseInt( this.next( 1 ) );
    };

    this.nextDouble = function() {
        return parseFloat( this.next( 1 ) );
    };

    this.nextString = function() {
        return this.next( 1 );
    };

    this.nextLine = function() {
        this.next( 0 );
    };
}

function FileOutputHandler() {
    this.resultantStringArray = new Array();

    this.addNewLine = function( newString ) {
        this.resultantStringArray.push( newString );
    };

    this.clearPercase = function() {
        this.resultantStringArray = new Array();
    };

    this.flushOutOutputToFile = function( outputFileName ) {
        var i , sz , res , currentDirectory , fsObj , outputFilePath;
        res = "";
        sz = this.resultantStringArray.length;
        for( i = 0 ; i < sz ; i++ ) {
            if( i != 0 ) {
                res += "\n";
            }
            res += this.resultantStringArray[ i ];
        }
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        outputFilePath = currentDirectory + "\\" + outputFileName;
        if( currentDirectory.charAt( 1 ) != ":" ) {
            //not local machine/windows
            outputFilePath = outputFileName;
        }
        fsObj.writeFileSync( outputFilePath , res );
        this.clearPercase();
    };
}

function CodeExecutioner() {
    this.irObj = new InputReader();
    this.psObj = new ProblemSolver();
    this.fohObj = new FileOutputHandler();

    this.runCode = function() {
        var testCases , i , hasMoreTestCases , isLocalMachine , localContext;
        isLocalMachine = false;
        try {
            if( __dirname != null && __dirname.charAt( 1 ) == ':' ) {
                //only on windows
                isLocalMachine = true;
            }
        }
        catch( ex ) {
            isLocalMachine = false;
        }
        if( isLocalMachine == true ) {
            //local machine runs on node and relies on file i/o
            print = console.log;
            if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
                localContext = this.fohObj;
                print = function() {
                    localContext.addNewLine.apply( localContext , arguments );
                }
            }
            this.irObj.readAllLinesFromFile( this.psObj.INPUT_FILE_NAME );
        }
        else {
            //server machine
            try {
                var rlObj = readline;
                //server runs on javasctipt v8 distribution and has readline method on global context
                this.irObj.readAllLines();
            }
            catch( ex ) {
                try {
                    var pObj = process;
                    //server runs on node
                    print = console.log;
                    this.irObj.readAllLinesFromNodeStdin();
                }
                catch( ex ) {
                    try {
                        var ipObj = importPackage;
                        //server runs on rhino
                        this.irObj.readAllLinesFromRhinoStdin();
                    }
                    catch( ex ) {
                        throw new Error( "Unknown javasctipt distribution!" );
                    }
                }
            }
        }
        if( this.psObj.HAS_TEST_CASES == true ) {
            testCases = this.irObj.nextInt();
            for( i = 0 ; i < testCases ; i++ ) {
                this.psObj.clearPerCase();
                this.psObj.getInput( this.irObj );
                this.psObj.solveCase();
            }
        }
        else {
            while( true ) {
                this.psObj.clearPerCase();
                hasMoreTestCases = this.psObj.getInput( this.irObj );
                if( hasMoreTestCases == false ) {
                    break;
                }
                this.psObj.solveCase();
            }
        }
        if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
            //only works for local machine(tested)
            this.fohObj.flushOutOutputToFile( this.psObj.OUTPUT_FILE_NAME );
        }
    };

    this.runCode();
}

new CodeExecutioner();

function ProblemSolver() {

    this.solveCase = function() {
        var res , i , j , a , b , c , d , e , hand , ma;
        res = 0;
        ma = -1;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a;
            }
        }
        hand = 0 ;
        for( i = ma ; i >= 2 ; i-- ) {
            if( this.arr[ i ] == 0 ) {
                continue;
            }
            if( hand < this.arr[ i ] ) {
                this.arr[ i ] -= hand;
                hand = 0;
            }
            else {
                hand -= this.arr[ i ];
                continue;
            }
            a = this.arr[ i ];
            b = Math.floor( a / this.k );
            c = b * ( i - 1 ) * 2;
            res += c;
            d = this.arr[ i ] - ( b * this.k );
            if( d > 0 ) {
                c = 1 * ( i - 1 ) * 2;
                res += c;
            }
            hand += d;
        }
        print( res );
    };

    this.getInput = function( irObj ) {
        var hasMoreInput , i;
        hasMoreInput = true;
        try {
            this.n = irObj.nextInt();
            this.k = irObj.nextInt();
            for( i = 0 ; i < this.n ; i++ ) {
                this.brr[ i ] = irObj.nextInt();
            }
        }
        catch( ex ) {
            hasMoreInput = false;
        }
        return hasMoreInput;
    };

    this.clearArraysPerCase = function() {
        var i;
        this.arr = new Array();
        this.brr = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
    };

    this.clearPerCase = function() {
        this.cn = 0;
        this.cc++;
        this.clearArraysPerCase();
    };

    this.HAS_TEST_CASES = false;
    this.INPUT_FILE_NAME = "test.in";
    this.OUTPUT_FILE_NAME = "out.txt";
    this.DO_OUTPUT_TO_FILE = false;

    this.declareAndFillArrays = function() {
        var i , j;
        this.srr = new Array();
        this.vis = new Array();
        this.arr = new Array();
        this.brr = new Array();
        this.memo = new Array();
        this.done = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.srr.push( "" );
            this.vis.push( 0 );
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
        for( i = 0 ; i < this.lim2 ; i++ ) {
            this.memo.push( new Array() );
            this.done.push( new Array() );
            for( j = 0 ; j < this.lim2 ; j++ ) {
                this.memo[ i ].push( -1 );
                this.done[ i ].push( 0 );
            }
        }
    };

    this.init = function() {
        this.lim1 = 2010;
        this.lim2 = 110;
        this.cc = 1;
        this.ind = 1;
        this.n = 0;
        this.cn = 0;
        this.declareAndFillArrays();
    };

    this.memsetArray1D = function( arrParam , val ) {
        var i;
        if( arrParam == null ) {
            throw new Error( "No array supplied in the parameter!" );
        }
        if( val == null ) {
            throw new Error( "No value for memset has been supplied in the parameter!" );
        }
        arrParam = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            arrParam.push( val );
        }
        return arrParam;
    };

    this.getStringLength = function( stringData ) {
        var len , lengthType;
        len = stringData.length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = stringData.length();
        }
        else {
            len = stringData.length;
        }
        return len;
    };

    this.init();
}

function InputReader() {
    this.allLines = new Array();
    this.currrentLineNumber = 0;
    this.currrentCharacterIndex = 0;

    this.readAllLines = function() {
        var singleLine;
        while( true ) {
            try {
                singleLine = readline();
                if( singleLine == null ) {
                    break;
                }
            }
            catch( ex ) {
                break;
            }
            this.allLines.push( singleLine );
        }
    };

    this.readAllLinesFromRhinoStdin = function() {
        importPackage( java.io );
        importPackage( java.lang );
        var singleLine , reader;
        reader = new BufferedReader( new InputStreamReader( System[ "in" ] ) );
        this.allLines = [];
        while( true ) {
            singleLine = reader.readLine();
            if( singleLine != null ) {
                this.allLines.push( singleLine );
            }
            else {
                break;
            }
        }
    };

    this.readAllLinesFromNodeStdin = function() {
        var fsObj , size , rawData;
        process.stdin.setEncoding( 'ascii' );
        fsObj = require( 'fs' );
        size = fsObj.fstatSync( process.stdin.fd ).size;
        rawData = fsObj.readSync( process.stdin.fd , size )[ 0 ];
        this.parseRawData( rawData );
    };

    this.parseRawData = function( data ) {
        var len , i , currentString;
        len = data.length;
        currentString = "";
        for( i = 0 ; i < len ; i++ ) {
            if( data[ i ] == '\r' ) {
            }
            else if( data[ i ] == '\n' ) {
                this.allLines.push( currentString );
                currentString = "";
            }
            else {
                currentString += data[ i ];
            }
        }
        if( currentString != "" ) {
            this.allLines.push( currentString );
        }
    };

    this.readAllLinesFromFile = function( inputFileName ) {
        var currentDirectory , fsObj , inputFilePath , rawData;
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        inputFilePath = currentDirectory + "\\" + inputFileName;
        rawData = fsObj.readFileSync( inputFilePath , "utf8" );
        this.parseRawData( rawData );
    };

    this.next = function( flag ) {
        var len , i , startIdx , res , endIdx , lengthType;
        len = this.allLines[ this.currrentLineNumber ].length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = this.allLines[ this.currrentLineNumber ].length();
        }
        if( flag == 0 ) {
            res = "";
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            this.currrentLineNumber++;
            this.currrentCharacterIndex = 0;
            return res;
        }
        while( true ) {
            if( this.currrentLineNumber >= this.allLines.length ) {
                throw new Error( "No more tokens available!" );
            }
            startIdx = -1;
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != ' '.charCodeAt( 0 ) && this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != '\t'.charCodeAt( 0 ) ) {
                    startIdx = i;
                    break;
                }
            }
            if( startIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
                continue;
            }
            res = "";
            endIdx = -1;
            for( i = startIdx ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == ' '.charCodeAt( 0 ) || this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == '\t'.charCodeAt( 0 ) ) {
                    endIdx = i;
                    break;
                }
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            if( endIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
            }
            else {
                this.currrentCharacterIndex = endIdx;
            }
            return res;
        }
    };

    this.nextInt = function() {
        return parseInt( this.next( 1 ) );
    };

    this.nextDouble = function() {
        return parseFloat( this.next( 1 ) );
    };

    this.nextString = function() {
        return this.next( 1 );
    };

    this.nextLine = function() {
        this.next( 0 );
    };
}

function FileOutputHandler() {
    this.resultantStringArray = new Array();

    this.addNewLine = function( newString ) {
        this.resultantStringArray.push( newString );
    };

    this.clearPercase = function() {
        this.resultantStringArray = new Array();
    };

    this.flushOutOutputToFile = function( outputFileName ) {
        var i , sz , res , currentDirectory , fsObj , outputFilePath;
        res = "";
        sz = this.resultantStringArray.length;
        for( i = 0 ; i < sz ; i++ ) {
            if( i != 0 ) {
                res += "\n";
            }
            res += this.resultantStringArray[ i ];
        }
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        outputFilePath = currentDirectory + "\\" + outputFileName;
        if( currentDirectory.charAt( 1 ) != ":" ) {
            //not local machine/windows
            outputFilePath = outputFileName;
        }
        fsObj.writeFileSync( outputFilePath , res );
        this.clearPercase();
    };
}

function CodeExecutioner() {
    this.irObj = new InputReader();
    this.psObj = new ProblemSolver();
    this.fohObj = new FileOutputHandler();

    this.runCode = function() {
        var testCases , i , hasMoreTestCases , isLocalMachine , localContext;
        isLocalMachine = false;
        try {
            if( __dirname != null && __dirname.charAt( 1 ) == ':' ) {
                //only on windows
                isLocalMachine = true;
            }
        }
        catch( ex ) {
            isLocalMachine = false;
        }
        if( isLocalMachine == true ) {
            //local machine runs on node and relies on file i/o
            print = console.log;
            if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
                localContext = this.fohObj;
                print = function() {
                    localContext.addNewLine.apply( localContext , arguments );
                }
            }
            this.irObj.readAllLinesFromFile( this.psObj.INPUT_FILE_NAME );
        }
        else {
            //server machine
            try {
                var rlObj = readline;
                //server runs on javasctipt v8 distribution and has readline method on global context
                this.irObj.readAllLines();
            }
            catch( ex ) {
                try {
                    var pObj = process;
                    //server runs on node
                    print = console.log;
                    this.irObj.readAllLinesFromNodeStdin();
                }
                catch( ex ) {
                    try {
                        var ipObj = importPackage;
                        //server runs on rhino
                        this.irObj.readAllLinesFromRhinoStdin();
                    }
                    catch( ex ) {
                        throw new Error( "Unknown javasctipt distribution!" );
                    }
                }
            }
        }
        if( this.psObj.HAS_TEST_CASES == true ) {
            testCases = this.irObj.nextInt();
            for( i = 0 ; i < testCases ; i++ ) {
                this.psObj.clearPerCase();
                this.psObj.getInput( this.irObj );
                this.psObj.solveCase();
            }
        }
        else {
            while( true ) {
                this.psObj.clearPerCase();
                hasMoreTestCases = this.psObj.getInput( this.irObj );
                if( hasMoreTestCases == false ) {
                    break;
                }
                this.psObj.solveCase();
            }
        }
        if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
            //only works for local machine(tested)
            this.fohObj.flushOutOutputToFile( this.psObj.OUTPUT_FILE_NAME );
        }
    };

    this.runCode();
}

new CodeExecutioner();

// 472B    Уроки дизайна задач: учимся у жизни

//var n = parseInt(readline());

// var input_line = readline().split(' ').map(Number);
var arr = readline().split(' ').map(Number);
var n = arr[0];
var k = arr[1];

var arr = readline().split(' ').map(Number);
arr.sort(function(a,b){return a-b;});
arr.reverse();

var out = 0;
var num = 0;
var sum_lift;
while (num < k) {
    out += (arr[num] - 1) * 2;

    if ((n - num) > k) {
        sum_lift = k;
        num += k;
    } else {
        sum_lift = n - num;
        num = n - 1;
    };
}

print(out);

var inp,n,k,arr;

inp=readline().split(" ");
n=+inp[0];
k=+inp[1];
arr=readline().split(" ").map(function(a){return +a;});

var ans=0;

arr.sort(function(a,b) {return b-a});
for(var i=0; i<n; i+=k) {
    var max=arr[i];
    for(var j=i; j<i+k; j++)
        max=Math.max(max,arr[j]);
    ans+=2*(max-1);
}

print(ans);

var inp,n,k,arr;

inp=readline().split(" ");
n=+inp[0];
k=+inp[1];
arr=readline().split(" ").map(function(a){return +a;});

var ans=0;

arr.sort(function(a,b) {return b-a});
print(arr);
for(var i=0; i<n; i+=k) {
    var max=arr[i];
    for(var j=i; j<i+k; j++)
        max=Math.max(max,arr[j]);
    ans+=2*(max-1);
}

print(ans);

var inp,n,k,arr;

inp=readline().split(" ");
n=+inp[0];
k=+inp[1];
arr=readline().split(" ").map(function(a){return +a;});
print(arr);

var ans=0;

arr.sort(function(a,b) {return b-a});
for(var i=0; i<n; i+=k) {
    var max=arr[i];
    for(var j=i; j<i+k; j++)
        max=Math.max(max,arr[j]);
    ans+=2*(max-1);
}

print(ans);

var nums = readline().split(' ');
var n = parseInt(nums[0]);
var k = parseInt(nums[1]);
var a_in = readline().split(' ');
var a = new Array();

for(var i=0;i<a_in.length;i++)
{
    a[i] = parseInt(a_in[i]);
}

a.sort(sortNum);
var x = 0;
var ans = 0;
while(x<n)
{
    ans+=(a[x]-1)*2;
	x+=k;
}
print(ans);

function sortNum(a, b)
{
    return a-b;
}

function ProblemSolver() {

    this.dp = function( i , hand ) {
        var res , r1 , ret , a , b , c , d , j;
        if( i < 2 ) {
            return 0;
        }
        ret = this.done[ i ][ hand ];
        res = this.memo[ i ][ hand ];
        if( ret == this.cc ) {
            return res;
        }
        this.done[ i ][ hand ] = this.cc;
        if( this.arr[ i ] == 0 ) {
            res = this.dp( i - 1 , hand );
            this.memo[ i ][ hand ] = res;
            return res;
        }
        res = ( 1 << 23 );
        a = this.arr[ i ];
        b = Math.floor( a / this.k );
        c = a - ( b * this.k );
        if( c != 0 ) {
            if( hand >= c ) {
                d = 2 * ( i - 1 ) * b;
                r1 = this.dp( i - 1 , hand - c ) + d;
                res = Math.min( res , r1 );
            }
            else {
                b++ ;
                d = 2 * ( i - 1 ) * b;
                c = ( b * this.k ) - a ;
                r1 = this.dp( i - 1 , c - hand ) + d;
                res = Math.min( res , r1 );
            }
        }
        else {
            d = 2 * ( i - 1 ) * b;
            r1 = this.dp( i - 1 , hand ) + d;
            res = Math.min( res , r1 );
        }
        this.memo[ i ][ hand ] = res;
        return res;
    };

    this.solveCase = function() {
        var res , i , j , a , b , c , d , e , hand , ma , prev , cur , inf;
        res = 0;
        inf = ( 1 << 23 );
        ma = -1;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a;
            }
        }
        if( ma > 500 ) {
            res = this.dp( 500 , 0 );
        }
        if( ma > 1000 ) {
            res = this.dp( 1000 , 0 );
        }
        if( ma > 1500 ) {
            res = this.dp( 1500 , 0 );
        }
        res = this.dp( ma , 0 );
        print( res );
    };

    this.solveCaseGreedy = function() {
        var res , i , j , a , b , c , d , e , hand , ma;
        res = 0;
        ma = -1;
        for( i = 0 ; i < this.n ; i++ ) {
            a = this.brr[ i ];
            this.arr[ a ]++;
            if( a > ma ) {
                ma = a;
            }
        }
        hand = 0;
        for( i = ma ; i >= 2 ; i-- ) {
            if( this.arr[ i ] == 0 ) {
                continue;
            }
            if( hand < this.arr[ i ] ) {
                this.arr[ i ] -= hand;
                hand = 0;
            }
            else {
                hand -= this.arr[ i ];
                continue;
            }
            a = this.arr[ i ];
            b = Math.floor( a / this.k );
            c = b * ( i - 1 ) * 2;
            res += c;
            d = this.arr[ i ] - ( b * this.k );
            if( d > 0 ) {
                c = 1 * ( i - 1 ) * 2;
                res += c;
            }
            hand += d;
        }
        print( res );
    };

    this.getInput = function( irObj ) {
        var hasMoreInput , i;
        hasMoreInput = true;
        try {
            this.n = irObj.nextInt();
            this.k = irObj.nextInt();
            for( i = 0 ; i < this.n ; i++ ) {
                this.brr[ i ] = irObj.nextInt();
            }
        }
        catch( ex ) {
            hasMoreInput = false;
        }
        return hasMoreInput;
    };

    this.clearArraysPerCase = function() {
        var i , j;
        this.arr = new Array();
        this.brr = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
    };

    this.clearPerCase = function() {
        this.cn = 0;
        this.cc++;
        this.clearArraysPerCase();
    };

    this.HAS_TEST_CASES = false;
    this.INPUT_FILE_NAME = "test.in";
    this.OUTPUT_FILE_NAME = "out.txt";
    this.DO_OUTPUT_TO_FILE = false;

    this.declareAndFillArrays = function() {
        var i , j;
        this.srr = new Array();
        this.vis = new Array();
        this.arr = new Array();
        this.brr = new Array();
        this.memo = new Array();
        this.done = new Array();
        this.adj_list = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.srr.push( "" );
            this.vis.push( 0 );
            this.arr.push( 0 );
            this.brr.push( 0 );
            this.adj_list.push( new Array() );
        }
        for( i = 0 ; i < this.lim1 ; i++ ) {
            this.memo.push( new Array() );
            this.done.push( new Array() );
            for( j = 0 ; j < this.lim1 ; j++ ) {
                this.memo[ i ].push( -1 );
                this.done[ i ].push( 0 );
            }
        }
    };

    this.init = function() {
        this.lim1 = 2010;
        this.lim2 = 2;
        this.lim3 = 2010;
        this.cc = 1;
        this.ind = 1;
        this.n = 0;
        this.cn = 0;
        this.declareAndFillArrays();
    };

    this.memsetArray1D = function( arrParam , val ) {
        var i;
        if( arrParam == null ) {
            throw new Error( "No array supplied in the parameter!" );
        }
        if( val == null ) {
            throw new Error( "No value for memset has been supplied in the parameter!" );
        }
        arrParam = new Array();
        for( i = 0 ; i < this.lim1 ; i++ ) {
            arrParam.push( val );
        }
        return arrParam;
    };

    this.getStringLength = function( stringData ) {
        var len , lengthType;
        len = stringData.length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = stringData.length();
        }
        else {
            len = stringData.length;
        }
        return len;
    };

    this.init();
}

function InputReader() {
    this.allLines = new Array();
    this.currrentLineNumber = 0;
    this.currrentCharacterIndex = 0;

    this.readAllLines = function() {
        var singleLine;
        while( true ) {
            try {
                singleLine = readline();
                if( singleLine == null ) {
                    break;
                }
            }
            catch( ex ) {
                break;
            }
            this.allLines.push( singleLine );
        }
    };

    this.readAllLinesFromRhinoStdin = function() {
        importPackage( java.io );
        importPackage( java.lang );
        var singleLine , reader;
        reader = new BufferedReader( new InputStreamReader( System[ "in" ] ) );
        this.allLines = [];
        while( true ) {
            singleLine = reader.readLine();
            if( singleLine != null ) {
                this.allLines.push( singleLine );
            }
            else {
                break;
            }
        }
    };

    this.readAllLinesFromNodeStdin = function() {
        var fsObj , size , rawData;
        process.stdin.setEncoding( 'ascii' );
        fsObj = require( 'fs' );
        size = fsObj.fstatSync( process.stdin.fd ).size;
        rawData = fsObj.readSync( process.stdin.fd , size )[ 0 ];
        this.parseRawData( rawData );
    };

    this.parseRawData = function( data ) {
        var len , i , currentString;
        len = data.length;
        currentString = "";
        for( i = 0 ; i < len ; i++ ) {
            if( data[ i ] == '\r' ) {
            }
            else if( data[ i ] == '\n' ) {
                this.allLines.push( currentString );
                currentString = "";
            }
            else {
                currentString += data[ i ];
            }
        }
        if( currentString != "" ) {
            this.allLines.push( currentString );
        }
    };

    this.readAllLinesFromFile = function( inputFileName ) {
        var currentDirectory , fsObj , inputFilePath , rawData;
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        inputFilePath = currentDirectory + "\\" + inputFileName;
        rawData = fsObj.readFileSync( inputFilePath , "utf8" );
        this.parseRawData( rawData );
    };

    this.next = function( flag ) {
        var len , i , startIdx , res , endIdx , lengthType;
        len = this.allLines[ this.currrentLineNumber ].length;
        lengthType = typeof len;
        if( lengthType == "function" ) {
            len = this.allLines[ this.currrentLineNumber ].length();
        }
        if( flag == 0 ) {
            res = "";
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            this.currrentLineNumber++;
            this.currrentCharacterIndex = 0;
            return res;
        }
        while( true ) {
            if( this.currrentLineNumber >= this.allLines.length ) {
                throw new Error( "No more tokens available!" );
            }
            startIdx = -1;
            for( i = this.currrentCharacterIndex ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != ' '.charCodeAt( 0 ) && this.allLines[ this.currrentLineNumber ].charCodeAt( i ) != '\t'.charCodeAt( 0 ) ) {
                    startIdx = i;
                    break;
                }
            }
            if( startIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
                continue;
            }
            res = "";
            endIdx = -1;
            for( i = startIdx ; i < len ; i++ ) {
                if( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == ' '.charCodeAt( 0 ) || this.allLines[ this.currrentLineNumber ].charCodeAt( i ) == '\t'.charCodeAt( 0 ) ) {
                    endIdx = i;
                    break;
                }
                res += String.fromCharCode( this.allLines[ this.currrentLineNumber ].charCodeAt( i ) );
            }
            if( endIdx == -1 ) {
                this.currrentLineNumber++;
                this.currrentCharacterIndex = 0;
            }
            else {
                this.currrentCharacterIndex = endIdx;
            }
            return res;
        }
    };

    this.nextInt = function() {
        return parseInt( this.next( 1 ) );
    };

    this.nextDouble = function() {
        return parseFloat( this.next( 1 ) );
    };

    this.nextString = function() {
        return this.next( 1 );
    };

    this.nextLine = function() {
        this.next( 0 );
    };
}

function FileOutputHandler() {
    this.resultantStringArray = new Array();

    this.addNewLine = function( newString ) {
        this.resultantStringArray.push( newString );
    };

    this.clearPercase = function() {
        this.resultantStringArray = new Array();
    };

    this.flushOutOutputToFile = function( outputFileName ) {
        var i , sz , res , currentDirectory , fsObj , outputFilePath;
        res = "";
        sz = this.resultantStringArray.length;
        for( i = 0 ; i < sz ; i++ ) {
            if( i != 0 ) {
                res += "\n";
            }
            res += this.resultantStringArray[ i ];
        }
        fsObj = require( 'fs' );
        currentDirectory = __dirname;
        outputFilePath = currentDirectory + "\\" + outputFileName;
        if( currentDirectory.charAt( 1 ) != ":" ) {
            //not local machine/windows
            outputFilePath = outputFileName;
        }
        fsObj.writeFileSync( outputFilePath , res );
        this.clearPercase();
    };
}

function CodeExecutioner() {
    this.irObj = new InputReader();
    this.psObj = new ProblemSolver();
    this.fohObj = new FileOutputHandler();

    this.runCode = function() {
        var testCases , i , hasMoreTestCases , isLocalMachine , localContext;
        isLocalMachine = false;
        try {
            if( __dirname != null && __dirname.charAt( 1 ) == ':' ) {
                //only on windows
                isLocalMachine = true;
            }
        }
        catch( ex ) {
            isLocalMachine = false;
        }
        if( isLocalMachine == true ) {
            //local machine runs on node and relies on file i/o
            print = console.log;
            if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
                localContext = this.fohObj;
                print = function() {
                    localContext.addNewLine.apply( localContext , arguments );
                }
            }
            this.irObj.readAllLinesFromFile( this.psObj.INPUT_FILE_NAME );
        }
        else {
            //server machine
            try {
                var rlObj = readline;
                //server runs on javasctipt v8 distribution and has readline method on global context
                this.irObj.readAllLines();
            }
            catch( ex ) {
                try {
                    var pObj = process;
                    //server runs on node
                    print = console.log;
                    this.irObj.readAllLinesFromNodeStdin();
                }
                catch( ex ) {
                    try {
                        var ipObj = importPackage;
                        //server runs on rhino
                        this.irObj.readAllLinesFromRhinoStdin();
                    }
                    catch( ex ) {
                        throw new Error( "Unknown javasctipt distribution!" );
                    }
                }
            }
        }
        if( this.psObj.HAS_TEST_CASES == true ) {
            testCases = this.irObj.nextInt();
            for( i = 0 ; i < testCases ; i++ ) {
                this.psObj.clearPerCase();
                this.psObj.getInput( this.irObj );
                this.psObj.solveCase();
            }
        }
        else {
            while( true ) {
                this.psObj.clearPerCase();
                hasMoreTestCases = this.psObj.getInput( this.irObj );
                if( hasMoreTestCases == false ) {
                    break;
                }
                this.psObj.solveCase();
            }
        }
        if( this.psObj.DO_OUTPUT_TO_FILE == true ) {
            //only works for local machine(tested)
            this.fohObj.flushOutOutputToFile( this.psObj.OUTPUT_FILE_NAME );
        }
    };

    this.runCode();
}

new CodeExecutioner();