import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class No00000627_Main {
	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	public static void main(String[] args) throws IOException {
		int t = Integer.parseInt(br.readLine());
		int x = Integer.parseInt(br.readLine());
		if(x != -1 && x != 1) {
			System.out.println("F");
			return;
		}
		for(int i = 1; i < t; i++) {
			int n = Integer.parseInt(br.readLine());
			if(x - n != -1 && x - n != 1) {
				System.out.println("F");
				return;
			}
			x = n;
		}
		System.out.println("T");
	}
}