#include <iostream>
#include <vector>

using namespace std;

int main() {
	int t, x;
	cin >> t;

	char ans = 'T';
	int p = 0;
	for (int i = 0; i < t; i++) {
		cin >> x;
		if (abs(x - p) == 1) {
			p = x;
		} else {
			ans = 'F';
			break;
		}
	}

	cout << ans << endl;
	return 0;
}