import java.util.*;

class Main {
	static Scanner sc = new Scanner(System.in);
	public static void main(String[] args) {
		
		int n = sc.nextInt();
		int[] ar = new int[n+1];
		ar[0] = 0;
		boolean F = true;
		for (int i=1; i<n+1; i++) {
			ar[i] = sc.nextInt();
			if (Math.abs(ar[i]-ar[i-1]) != 1) F = false;
		}
		
		System.out.println(F?"T":"F");
		
	}
}