using System;

public class Program {
	public void Solve() {
		string[] s = Console.ReadLine().Split(':');
		DateTime dt = new DateTime(2017, 11, 09, int.Parse(s[0]), int.Parse(s[1]), 0);
		dt = dt.AddMinutes(5);
		Console.WriteLine(dt.TimeOfDay.ToString().Substring(0, 5));
	}
	
	public static void Main(string[] args) {
		Program program = new Program();
		program.Solve();
	}
}