#include<iostream>
#include<cassert>
using namespace std;
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int N;
	string S;
	cin>>N>>S;
	for(int i=0;i+3<=S.size();i++)if(S.substr(i,3)=="404")
	{
		cout<<"Found"<<endl;
		return 0;
	}
	cout<<"NotFound"<<endl;
}