#include <iostream>

int main() {
    using namespace std;
    int t;
    int x[100];
    int p = 0;
    cin >> t;
    for (int i = 0; i < t; i++) {
        cin >> x[i];
    }
    for (int i = 0; i < t; i++) {
        int d = abs(p - x[i]);
        if (d == 1) {
            p = x[i];
        } else {
            cout << "F" << endl;
            return 0;
        }
    }
    cout << "T" << endl;
}