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

int main(){
	int a;
	cin>>a;
	for(int i=0;i<a;i++){
		char b[100];
		cin>>b[i];
		if(b[i]=='Y'){
			cout<<"Four"<<endl;
			return 0;
		}
	}
	cout<<"Three"<<endl;
}
