using System;

namespace _652
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] s = Console.ReadLine().Split();
            int a = (int)(60 * (double.Parse(s[2].Substring(3,s[2].Length - 3)) + 0.01)) + 900;
            int time = int.Parse(s[0]) * 60 + int.Parse(s[1]); time += a;
            int hour = time / 60 % 24;
            if (hour < 10) Console.Write(0);
            Console.Write(hour + ":");
            int minute = time % 60;
            if (minute < 10) Console.Write(0);
            Console.WriteLine(minute);
        }
    }
}