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

int main() {
    int n;
    string s;
    cin >> n >> s;
    for (int i = 0; i < s.size()-2; i++) {
        if (s.at(i) == '4' && s.at(i + 1) == '0' && s.at(i + 2) == '4') {
            cout << "Found" << endl;
            system("pause");
            return 0;
        }
    }
    cout << "NotFound" << endl;

    system("pause");
}