SumSeconds

import java.util.Scanner;

public class Problem7_SumSeconds {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int a = Integer.parseInt(scanner.nextLine());
        int b = Integer.parseInt(scanner.nextLine());
        int c = Integer.parseInt(scanner.nextLine());
        int sum = a + b + c;
        int minutes = sum / 60;
        int seconds = sum % 60;

        if (seconds >= 10 && seconds <= 59) {
            System.out.println(minutes + ":" + seconds);
        } else if (seconds > 60 && seconds < 119) {
            System.out.println(minutes + ":1" + (seconds - 60));
        } else if (seconds > 120 && seconds < 179) {
            System.out.println(minutes + ":2" + (seconds - 120));
        } else if (seconds < 10) {
            System.out.println(minutes + ":0" + seconds);
        }
    }
}