public class Digest {
	public static void main(String[] args) {
		
	}
}
@@ -21,50 +21,953 @@
 %7B%0A%09p
-ublic static void main(String%5B%5D args) %7B%0A%09%09
+rivate static String%5B%5D algorithms = %7B%22MD5%22, %22SHA-1%22, %22SHA-256%22%7D;%0A%09public static void main(String%5B%5D args) %7B%0A%09%09if (args.length %3C 2 %7C%7C args%5B0%5D.equals(%22--help%22)) %7B%0A%09%09%09printUsageAndExit();%0A%09%09%7D%0A%09%09String algorithm;%0A%09%09try %7B%0A%09%09%09algorithm = checkAlgorithm(args%5B0%5D);%0A%09%09%7D catch (IllegalArgumentException ex) %7B%0A%09%09%09System.err.println(ex.getMessage());%0A%09%09%09printUsageAndExit();%0A%09%09%09return;%0A%09%09%7D%0A%09%7D%0A%09%0A%09private static String checkAlgorithm(String algorithm) %7B%0A%09%09for (String elem : algorithms) %7B%0A%09%09%09if (algorithm.equals(elem)) %7B%0A%09%09%09%09return algorithm;%0A%09%09%09%7D%0A%09%09%7D%0A%09%09throw new IllegalArgumentException(%22Unrecognised algorithm: %22 + algorithm);%0A%09%7D%0A%09%0A%09private static void printUsageAndExit() %7B%0A%09%09System.err.println(%22Usage: java Digest %3Cfunction_name%3E %3Cfile1%3E file2%3E ...%5Cn%22 +%0A%09%09                   %22    %3Cfunction_name%3E options include: %22);%0A%09%09for (String algorithm : algorithms) %7B%0A%09%09%09System.err.println(%22                                    %22 + algorithm);%0A%09%09%7D%0A%09%09System.exit(1);
 %0A%09%7D%0A

Add basic input parsing