#include <bits/stdc++.h>
using namespace std;

int main()
{
    int N;
    cin >> N;
    string S;
    cin >> S;

    for (int i = 0; i < N - 2; i++)
    {
        if (S.substr(i, 3) == "404")
        {
            cout << "Found";
            return 0;
        }
    }
    cout << "NotFound";
}