Minutes + 15

import java.text.DecimalFormat;
import java.util.Scanner;

public class Minutes15 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int hour = Integer.parseInt(scanner.nextLine());
        int min = Integer.parseInt(scanner.nextLine());
        min = min + 15;

        if (min >= 60) {
                hour = hour + 1;
                min = min - 60;
            } if (hour >= 24) {
            hour = hour - 24;
        } if (min < 10) {
            System.out.println(hour + ":0" + min);
        } else {
            System.out.printf("%d:%d", hour, min);
        }

    }
}