#include <bits/stdc++.h>
using namespace std;
int main() {
  int n,i;
  string s;
  cin>>n;
  for(i=0;i<n;i++) {
    cin>>s;
    if (s=="Y") break;
  }
  if (s=="Y") cout<<"Four"<<endl;
  else cout<<"Three"<<endl;
}
