using System;
using System.Collections.Generic;
using System.Linq;
using static System.Console;

class Program
{
    static void Main()
    {
        var abs = ReadLine().Split();
        var a = int.Parse(abs[0]);
        var b = int.Parse(abs[1]);
        var j = decimal.Parse(abs[2].Substring(3)) - 9;

        a += (int)Math.Floor(j);
        if ((j - (int)Math.Floor(j)) * 60 >= 60) a++;
        b += (int)(j - (int)Math.Floor(j)) * 60 % 60;
        a %= 24;
        WriteLine($"{a:00}:{b:00}");
    }
}