using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static char[][] SList(long n) => Enumerable.Repeat(0, (int)n).Select(_ => ReadLine().ToCharArray()).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var t = NN;
        var a = new int[t + 1];
        for (var i = 1; i <= t; ++i) a[i] = NN;
        for (var i = 0; i + 1 <= t; ++i) if (Math.Abs(a[i] - a[i + 1]) != 1)
        {
            WriteLine("F");
            return;
        }
        WriteLine("T");
    }
}