package com.company;

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int h = Integer.parseInt(scanner.nextLine());
        int m = Integer.parseInt(scanner.nextLine());

        int totalM = m + 15;
        int totalH = h;
        if (totalM >= 60){
            totalH = totalH + 1;
            totalM = totalM % 60;
        }
        String minFormat = "";
        if (totalM < 10){
            minFormat = "0" + totalM;
        } else {
            minFormat = ""+totalM;
        }

        if (totalH >= 24){
            totalH = totalH - 24;
        }

        System.out.printf("%d:%s", totalH,minFormat);

    }
}