HomeWork

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.text.DecimalFormat;

public class SportPlayers {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

        int firstTime = Integer.parseInt(reader.readLine());
        int secondTime = Integer.parseInt(reader.readLine());
        int thirdTime = Integer.parseInt(reader.readLine());

        int sum = firstTime + secondTime + thirdTime;

        int minutes = sum / 60;
        int seconds = sum % 60;

        if (seconds > 9) {
            System.out.println(String.format("%d:%d", minutes, seconds));
        }else{
            System.out.println(String.format("%d:0%d", minutes, seconds));
        }


    }
}