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

int main(){

    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    ll N;
    string S;
    cin>>N>>S;
    for(int i=0;i<N-2;i++){
        if(S.substr(i,3)=="404"){
            cout<<"Found"<<endl;
            return 0;
        }
    }
    cout<<"NotFound"<<endl;
    
}