#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)s; i < (int)e; ++i)
#define all(a) (a).begin(), (a).end()

int main() {
    cin.tie(nullptr);
    
    int N;
    string S;
    cin >> N >> S;
    
    bool found = false;
    rep(i, 0, N - 2) if (S.substr(i, 3) == "404") found = true;
    
    if (found) cout << "Found\n";
    else cout << "NotFound\n";
}