First

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Globalization;

namespace _1000DaysAfterBirth
{
    class Program
    {
        static void Main()
        {
            int firstSeconds = int.Parse(Console.ReadLine());
            int secondSeconds = int.Parse(Console.ReadLine());
            int thirdSeconds = int.Parse(Console.ReadLine());

            int totalSeconds = firstSeconds + secondSeconds + thirdSeconds;

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

            Console.WriteLine($"{minutes}:{seconds:d2}");
        }
    }
}