#include <bits/stdc++.h>

using namespace std;

template <typename T> T gcd(T x, T y) {
  if (y == 0)
    return x;
  return gcd(y, x % y);
}

template <typename T> T lcm(T x, T y) {
  if (x == 0 || y == 0)
    return 0;
  return x / gcd(x, y) * y;
}

int main() {
  int N;
  cin >> N;
  int now = 0;
  for (int i = 0; i < N; i++) {
    int X;
    cin >> X;
    if (now + 1 != X && now - 1 != X) {
      cout << 'F' << endl;
      return 0;
    } else {
      now = X;
    }
  }
  cout << 'T' << endl;
}