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

int main() {
	int n;
	cin >> n;

	vector<int> v(n + 1, 0);
	for (int i = 1; i < n + 1; i++) {
		cin >> v.at(i);
	}

	int f = 0;
	for (int i = 1; i < n + 1; i++) {
		if (v.at(i) + 1 == v.at(i-1)) {
			continue;
		}
		else if (v.at(i) - 1 == v.at(i - 1)) {
			continue;
		}
		else {
			f = 1;
			break;
		}
	}

	if (f) {
		cout << 'F' << endl;
	}
	else {
		cout << 'T' << endl;
	}
}