Time plus 15 seconds

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

namespace Time_15_Minutes
{
    class Program
    {
        static void Main(string[] args)
        {
            var hours = int.Parse(Console.ReadLine());
            var mins = int.Parse(Console.ReadLine()) + 15;

            if (mins > 59)
            {
                hours += 1;
                mins = mins - 60;
            }
            if (hours == 24)
            {
                hours = 0;
            }
            Console.WriteLine("{0}:{1:D2}", hours, mins);
        }
    }
}