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

int N;
char A[109];

int main() {
	cin >> N;
	for (int i = 1; i <= N; i++) cin >> A[i];
	for (int i = 1; i <= N - 2; i++) {
		if (A[i] == '4' && A[i + 1] == '0' && A[i + 2] == '4') {cout << "Found" << endl; return 0;}
	}
	cout << "NotFound" << endl;
	return 0;
}