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

int main() {
	int t; cin >> t;
	int now = 0;
	while(t--) {
		int x; cin >> x;
		if(abs(x - now) != 1) {
			cout << "F" << '\n';
			return 0;
		}
		now = x;
	}
	cout << "T" << '\n';
	return 0;
}