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

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N; cin >> N;
    string s; cin >> s;
    for(int i=0; i<N-2; i++){
        string t = s.substr(i,3);
        if(t == "404"){
            cout << "Found" << endl;
            return 0;
        }
    }
    cout << "NotFound" << endl;
}