sum sec

import java.util.Scanner;

public class SumSeconds01 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int athlete1 = Integer.parseInt(scanner.nextLine());
        int athlete2 = Integer.parseInt(scanner.nextLine());
        int athlete3 = Integer.parseInt(scanner.nextLine());

        int allTime = athlete1+athlete2+athlete3;

        int min = allTime/60;
        int sec = allTime%60;

        System.out.printf("%d:%02d", min, sec);
    }
}