#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

int main() {
  int n;
  cin >> n;

  int x = 0;
  for (int i = 0; i < n; i++) {
    int xx;
    cin >> xx;
    if (abs(x - xx) != 1) {
      cout << "F" << endl;
      return 0;
    }
    x = xx;
  }
  cout << "T" << endl;
}