View Code of Problem 56

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scanner=new Scanner(System.in);
		String[] start=scanner.nextLine().split(":");
		String[] end=scanner.nextLine().split(":");
		double s=0;
		double e=0;
		s=Integer.parseInt(start[0])*3600+Integer.parseInt(start[1])*60+Integer.parseInt(start[2]);
		e=Integer.parseInt(end[0])*3600+Integer.parseInt(end[1])*60+Integer.parseInt(end[2]);
		double ans=e-s;
		System.out.print((int)ans/3600+":");
		ans=ans%3600;
		System.out.printf("%02d:",(int)ans/60);
		ans%=60;
		System.out.printf("%02d",(int)ans);
	}

}