time+15 minutes

using System;

namespace _15minutes
{
    class Program
    {
        static void Main(string[] args)
        {
            int startHour = int.Parse(Console.ReadLine());
            int startMinutes = int.Parse(Console.ReadLine());
            int convertedTime = startHour * 60 + startMinutes;
            int plus15 = convertedTime + 15;
            int finalHour = plus15 / 60;
            int finalMinutes = plus15 % 60;
            if (finalHour >=24)
            {
                finalHour -= 24;
            }
            else if (finalHour <24)
            {
                finalHour=finalHour * 1;
            }
            if (finalMinutes <9)
            {
                Console.WriteLine($"{finalHour}:0{finalMinutes}");
            }
            else if(finalMinutes >=10)
            {
                Console.WriteLine($"{finalHour}:{finalMinutes}");
            }
        }
    }
}