using System;

namespace _15min_Time
{
    class Program
    {
        static void Main(string[] args)
        {
            int hours = int.Parse(Console.ReadLine());
            int minutes = int.Parse(Console.ReadLine());


            if (minutes > 59)
            {
                hours = hours + 1;
                minutes = minutes - 60;
            }
            else if (minutes > 45)
            {
                hours = hours + 1;
                minutes = minutes - 60;
            }
            else
            {
                minutes = minutes + 15;
            }
            if (hours > 23)
            {
                hours = hours - 24;
            }
            if (minutes < 10)
            {
                Console.WriteLine(hours + ":" + "0" + minutes);
            }
            else
            {
                Console.WriteLine(hours + ":" + minutes);
            }

        }
    }
}