class Program
{
    static void Main(string[] args)
    {
        int range = int.Parse(Console.ReadLine()!);
        int ans = range / 10 * 6;

        DateTime dateTime = DateTime.Parse("2025/01/01 10:00:00");
        TimeSpan timeSpan = new TimeSpan(ans / 60, ans % 60, 0);
        dateTime += timeSpan;

        Console.WriteLine(dateTime.ToString("HH:mm"));
    }
}