using System;

public class Hello
{
    public static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        var pre = 0;
        for (int i = 0; i < n; i++)
        {
            var w = int.Parse(Console.ReadLine().Trim());
            if (Math.Abs(pre - w) != 1) { Console.WriteLine('F'); goto end; }
            pre = w;
        }
        Console.WriteLine('T');
        end:;
    }
}