#include <bits/stdc++.h>

using namespace std;

int main() {
    int t, p = 0;
    
    cin >> t;
    
    int tmp;
    for (int i = 0; i < t; i++) {
        cin >> tmp;
        if (abs(p - tmp) != 1) {
            cout << "F" << endl;
            return 0;
        }
        p = tmp;
    }
    
    cout << "T" << endl;
    
    return 0;
}