@@ -0,0 +1,844 @@
+import java.io.*;%0Aimport java.util.*;%0A%0Ainterface AdvancedArithmetic%7B%0A   int divisorSum( int n );%0A%7D%0A%0A%0Aclass Calculator implements AdvancedArithmetic %7B%0A    %0A    public int divisorSum( int n ) %7B%0A        %0A        int sum = 1;%0A        // 1 and n are always divisors%0A        // Greatest divisor %3C= n / 2%0A        for ( int i = 2; i %3C= n / 2; ++i ) %7B%0A            if ( n %25 i == 0 ) %7B%0A                sum += i;%0A            %7D%0A        %7D%0A        %0A        return sum + n;%0A        %0A    %7D%0A    %0A%7D%0A%0Apublic class Solution %7B%0A%0A    public static void main( String%5B%5D args ) %7B%0A%0A        Scanner sc = new Scanner( System.in );%0A        int n = sc.nextInt();%0A      %09AdvancedArithmetic myCalculator = new Calculator(); %0A        int sum = myCalculator.divisorSum( n );%0A        System.out.println(%22I implemented: AdvancedArithmetic%5Cn%22 + sum);%0A    %09sc.close();%0A    %09%0A    %7D%0A%0A%7D%0A

Add day 19 solution