#include <iostream>
using namespace std;
int main(void) {
	int t, x;
	cin >> t;
	int pos = 0;
	bool ok = true;
	for (int i = 0; i < t; ++i) {
		cin >> x;
		if (abs(x - pos) != 1) 
			ok = false;
		pos = x;
	}
	cout << (ok ? "T" : "F") << endl;
	return 0;
}