#include <bits/stdc++.h>
using namespace std;

int main() {
	int t;
	cin >> t;
	int x[t + 1]{};
	for (int i = 1; i <= t; i++) {
		cin >> x[i];
	}
	for (int i = 1; i <= t; i++) {
		if (abs(x[i] - x[i - 1]) != 1) {
			cout << "F" << endl;
			return 0;
		}
	}
	cout << "T" << endl;
	return 0;
}