_01_Problem

import java.util.Scanner;

public class _01_Problem {

    public static void main(String[] args) {
        @SuppressWarnings("resource")
        Scanner input = new Scanner(System.in);
        String start = input.nextLine();
        String end = input.nextLine();
        String[] startArr = start.split(":");
        String[] endArr = end.split(":");

        //System.out.println(Arrays.toString(startArr));
        //System.out.println(Arrays.toString(endArr));
        Long startHours = Long.parseLong(startArr[0]);
        Long startMin = Long.parseLong(startArr[1]);
        Long startSec = Long.parseLong(startArr[2]);

        Long endHours = Long.parseLong(endArr[0]);
        Long endMin = Long.parseLong(endArr[1]);
        Long endSec = Long.parseLong(endArr[2]);

        long startInSec = startSec + startMin*60 + startHours*60*60;
        long endInSec = endSec + endMin*60 + endHours*60*60;

        long timeDiff = Math.abs(startInSec - endInSec);
        //System.out.println(timeDiff);
        long seconds = timeDiff % 60;
        //System.out.println(seconds);
        long minutes = (timeDiff % 3600)/60;
        long hours = timeDiff / 3600;
        //System.out.println(minutes);
        //System.out.println(hours);
        System.out.printf("%s:%02d:%02d", hours, minutes, seconds);
    }
}