using System;

class Program
{
    static void Main()
    {
        int N = int.Parse(Console.ReadLine());
        string S = Console.ReadLine();

        for (int i = 0; i + 2 < N; i++)
        {
            if (S[i] == '4' && S[i + 1] == '0' && S[i + 2] == '4')
            {
                Console.WriteLine("Found");
                return;
            }
        }

        Console.WriteLine("NotFound");
    }
}