#include <iostream>
using namespace std;

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