#include<iostream>
#include<algorithm>
#include <vector>
#include<cmath>
using namespace std;
typedef long long int lont;
int main() {
	int T;
	cin >> T;
	int cnt = 0;
	vector <int>vec(T);
	for (int ia = 0; ia < T; ia++) {
		cin >> vec.at(ia);
	}
	if (vec.at(0) != 1&&vec.at(0)!=-1) {
		cout << 'F' << endl;
	}
	else {
		for (int ib = 1; ib < T; ib++) {
			if (abs(vec.at(ib - 1)-vec.at(ib)) > 1|| abs(vec.at(ib - 1) - vec.at(ib)) ==0) {
				cnt++;
			}
		}
		if (cnt)cout << 'F' << endl;
		if (!cnt)cout << 'T' << endl;
	}

}