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

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  ll N;
  string S;
  cin >> N >> S;

  for(ll i = 0; i < N - 2; i++) {
    if(S.substr(i, 3) == "404") {
      cout << "Found\n";
      return 0;
    }
  }

  cout << "NotFound\n";
}