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

#ifndef LOCAL
#define debug(...)
#endif

#define SZ(x) ((int) x.size())
#define int   long long
#define endl '\n'
#define pii   pair<int, int>

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

signed main() 
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int tc = 1;
    // cin >> tc;
    while (tc--) {
        test_case();
    }
}