using System;

class Program {
  static void Main() {
    int t = int.Parse(Console.ReadLine());
    int p = 0;
    var a = "T";
    while (t-- > 0) {
      int x = int.Parse(Console.ReadLine());
      if (!(p - 1 == x || p + 1 == x)) a = "F";
      p = x;
    }
    Console.WriteLine(a);
  }
}