#include <bits/stdc++.h>
using namespace std;
int main() {
	int n; cin >> n;
	char s[102];
	string ans = "Three";
	for(int i=0;i<n;i++){
		cin >> s[i];
		if(s[i]=='Y'){
			ans = "Four";
		}
	}
	cout << ans << endl;
	return 0;
}