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

void fast_io() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
}

int main() {
	fast_io();
	int n;
	cin >> n;
	string s;
	cin >> s;
	for (int i = 0; i <= n - 2; i++) {
		if (s.substr(i, 3) == "404") {
			cout << "Found" << endl;
			return 0;
		}
	}
	cout << "Not Found" << endl;
}