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

int main(){
  int T;
  cin >> T;
  vector<int> X(T);
  for(int i=0;i<T;i++) cin >> X[i];
  bool flag = true;
  if(abs(X[0]) != 1) flag = false;
  for(int i=0;i<T-1;i++) if(abs(X[i]-X[i+1]) != 1) flag = false;
  if(flag) cout << "T" << endl;
  else cout << "F" << endl;
}