#include <iostream>
#include <algorithm>
#include <string>
using namespace std;

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

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

    return 0;
}