01. Sum Seconds

using System;

namespace SumSeconds
{
    class Program
    {
        static void Main()
        {
            int firstTime = int.Parse(Console.ReadLine());
            int secondTime = int.Parse(Console.ReadLine());
            int thirdTime = int.Parse(Console.ReadLine());
            int total = firstTime + secondTime + thirdTime;
            int minutes = total / 60;
            int seconds = total % 60;

            if (seconds < 10)
            {
                Console.WriteLine($"{minutes}:0{seconds}");
            }
            else
            {
                Console.WriteLine($"{minutes}:{seconds}");
            }
        }
    }
}