#include <iostream>
#include <stdlib.h>
using namespace std;

int main() {
	int t, flag;
	cin >> t;
	int x[t + 1];
	for (int i = 1; i <= t; i++) {
		cin >> x[i];
	}
	x[0] = 0;

	for (int i = 1; i <= t; i++) {
		if (x[i] == x[i - 1] + 1 || x[i] == x[i - 1] - 1) {
			flag = 1;
		}
		else {
			flag = 0;
			break;
		}
	}

	if (flag == 0) {
		cout << "F" << endl;
	}
	else {
		cout << "T" << endl;
	}
	
	return 0;
}