07a. Sum Seconds

/*
 * Simple Conditions
 */
import java.util.Scanner;

public class _07a_SumSeconds
{
    public static void main(String[] args)
    {
        Scanner scan = new Scanner(System.in);

        int firstTime = Integer.parseInt(scan.nextLine());
        int secondTime = Integer.parseInt(scan.nextLine());
        int thirdTime = Integer.parseInt(scan.nextLine());

        int totalTimeSeconds = firstTime + secondTime + thirdTime;

        System.out.printf("%d:%02d", (totalTimeSeconds / 60), (totalTimeSeconds % 60));
    }
}