using System;

namespace Time_15Min
{
    class Program
    {
        static void Main(string[] args)
        {
            int hour = int.Parse(Console.ReadLine());
            int min = int.Parse(Console.ReadLine());

            int sum = ((hour * 60) + min + 15);
            int resultHour = sum / 60;
            if (resultHour >= 24)
            {
                resultHour -= 24;
            }
            int resultMin = sum % 60;

            Console.WriteLine($"{resultHour}:{resultMin:D2}");
        }
    }
}