#include <iostream>
using namespace std;

int main() {
	int n, p = 0, x;
	bool flag = true;
	cin >> n;

	for (int t = 0; t<n; t++) {
		cin >> x;

		if (x == p || !(p - x == 1 || p - x != -1)) {
			flag = false;
		}
		p = x;
	}
	if(flag)cout << "T" << endl;
	else
	{
		cout << "F" << endl;
	}

	return 0;
}