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

int main() {
  int N;
  cin >> N;
  int now = 0;
  char ans = 'T';
  for (int i = 0, x; i < N && cin >> x; i++) {
    if (abs(now - x) != 1) ans = 'F';
    now = x;
  }
  cout << ans << "\n";
}