using System;

namespace Time15sec
{
    class Program
    {
        static void Main(string[] args)
        {
            double h = double.Parse(Console.ReadLine());
            double m = double.Parse(Console.ReadLine());

            m += 15;

            if (m >= 60)
            {
                m = m - 60;
                h += 1;
            }

            if (h >= 24)
            {
                h = 0;
            }

            Console.WriteLine($"{h}:{m:d2}");
        }
    }
}