using System;

public class Program

{

    public static void Main()

    {

        int num1 = int.Parse(Console.ReadLine());

        int num2 = int.Parse(Console.ReadLine());

        int num3 = int.Parse(Console.ReadLine());

        int seconds = num1 + num2 + num3;

        int minutes = 0;

        if (seconds >= 60)

        {

            minutes += 1;

            seconds -= 60;

        }

        if (seconds >= 60)

        {

            minutes += 1;

            seconds -= 60;

        }

        if (seconds < 10)

        {

            Console.WriteLine(minutes + ":0" + seconds);

        }

        else

        {

            Console.WriteLine(minutes + ":" + seconds);

        }

    }

}