import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int t = sc.nextInt();
        int [] x = new int [t];
        for(int i = 0; i < t; i++) {
            x[i] = sc.nextInt();
        }
        if(judge(x)) {
            System.out.println("T");
        } else {
            System.out.println("F");
        }
    }
    
    static boolean judge(int [] x) {
        int now = 0;
        for(int i = 0; i < x.length; i++) {
            if(Math.abs(now - x[i]) != 1) {
                return false;
            }
            now = x[i];
        }
        return true;
    }
}