#include <iostream>
using namespace std;

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

    int p = 0;
    for (int i = 0; i < T; i++) {
        int X;
        cin >> X;

        if (abs(X - p) != 1) {
            cout << "F" << endl;
            return 0;
        }

        p = X;
    }
    cout << "T" << endl;

    return 0;
}