#include <iostream>
#include <list>
#include <vector>
#include <string>
#include <stdio.h>
#include <stdint.h>
#include <iomanip>
using namespace std;

using uint = unsigned int;
using ll = long long;

#define CIN( LL , A ) LL A; cin >> A 
#define GETLINE( A ) string A; getline( cin , A ) 
#define FOR_ITR( ARRAY , ITR , END ) for( auto ITR = ARRAY .begin() , END = ARRAY .end() ; ITR != END ; ITR ++ ) 

int main()
{

  CIN( ll , T );
  ll X_prev = 0;
  ll X_next;

  for( ll i = 0 ; i < T ; i++ ){

    cin >> X_next;
    const ll d = X_next - X_prev;

    if( d != 1 && d != -1 ){

      cout << "F" << endl;
      return 0;

    }

    X_prev = X_next;
    
  }

  cout << "T" << endl;
  return 0;

}