Sum Seconds - if

using System;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            int firstCompetitor = int.Parse(Console.ReadLine());
            int secondCompetitor = int.Parse(Console.ReadLine());
            int thirdCompetitor = int.Parse(Console.ReadLine());

            int seconds = firstCompetitor + secondCompetitor + thirdCompetitor;
            int minutes = 0;

            if (seconds <= 59)
            {
                minutes = 0;
                seconds = seconds;
            } else if (seconds > 59 && seconds <= 119)
            {
                minutes++;
                seconds = seconds - 60;
            } else if (seconds > 119 && seconds <= 179)
            {
                minutes += 2;
                seconds = seconds - 120;
            }
            if (seconds < 10)
            {
                Console.WriteLine(minutes + ":" + "0" + seconds);
            } else
            {
                Console.WriteLine(minutes + ":" + seconds);
            }
        }
    }
}