SumSeconds

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

public class SumSeconds {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int player1 = Integer.parseInt(scanner.nextLine());
        int player2 = Integer.parseInt(scanner.nextLine());
        int player3 = Integer.parseInt(scanner.nextLine());
        double timeSumSec = player1 + player2 + player3;
        double sec = timeSumSec % 60;

        if (timeSumSec >= 0 && timeSumSec <= 59) {

            if (sec < 10)

                System.out.print("0:0" + (int)Math.floor(sec));

            else if (sec >= 10)
                System.out.println("0:" + (int)Math.floor(sec));
        }
        else if (timeSumSec >= 60 && timeSumSec <= 119) {

            System.out.print("1:");

            if (sec < 10)

                System.out.print("0" + (int)Math.floor(sec));

            else if (sec >= 10)
                System.out.println((int)Math.floor(sec));
        }
        else if (timeSumSec >= 120 && timeSumSec <= 179) {

            System.out.print("2:");
            if (sec < 10)

                System.out.print("0" + (int)Math.floor(sec));
            else if (sec >= 10)
                System.out.println((int)Math.floor(sec));
        }
    }}