using System;

namespace _652
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] s = Console.ReadLine().Split();
            var x = double.Parse(s[2].Substring(3, s[2].Length - 3));
            double a = 60 * x + 900;
            if (1 - (x % 1) < 0.001) a++;
            double time = int.Parse(s[0]) * 60 + int.Parse(s[1]); time += a;
            double hour = time / 60 % 24;
            if (hour < 10) Console.Write(0);
            Console.Write((int)hour + ":");
            double minute = time % 60;
            if (minute < 10) Console.Write(0);
            Console.WriteLine((int)minute);
        }
    }
}