#include<iostream>
using namespace std;
 
int main(){
int n;
  bool c=false;
  char s[105];
  cin>>n;
  for(int i=0;i<n;i++){
  cin>>s[i];
    if(s[i]=='Y')c=true;
  }
if(c==true)cout<<"Four"<<endl;
  else cout<<"Three"<<endl;
}