View Code of Problem 56

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		String string = scanner.nextLine();
		String str = scanner.nextLine();
		String[] a = string.split(":");
		String[] b = str.split(":");
		int h1 = Integer.parseInt(a[2]) + Integer.parseInt(a[1]) * 60 +Integer.parseInt(a[0]) * 3600;
		int h2 = Integer.parseInt(b[2]) + Integer.parseInt(b[1]) * 60 +Integer.parseInt(b[0]) * 3600;
		int t = Math.abs(h1 - h2);
		int h = t / 3600;
		int m = t % 3600 / 60;
		int s = t % 3600 % 60;
		System.out.printf("%d:%02d:%02d",h,m,s);
	}
}