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

int main() {
  int T; cin >> T;
  int now = 0;
  for(int i = 0; i < T; i++){
    int X; cin >> X;
    if(abs(X-now) == 1){
      now = X;
    }else{
      cout << "F" << endl;
      return 0;
    }
  }
  cout << "T" << endl;
}