using System;
using System.Collections.Generic;
using System.Linq;

namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            int mae = 0;
            bool ret = true;
            for (int i = 0; i < n; i++)
            {
                int x = int.Parse(Console.ReadLine());
                if (Math.Abs(mae - x) != 1) ret = false;
                mae = x;
            }
            Console.WriteLine(ret ? "T" : "F");
        }
    }
}