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

int main(){
    int n;
    string s;
    cin >> n >> s;
    bool check = 0;
    for(int j = 0;j < n - 2;j++){
        if(s.substr(j,3) == "404"){
            check = 1;
        }
    }
    if(check)cout << "Found" << endl;
    else cout << "NotFound" << endl;
    return 0;
}