#include <bits/stdc++.h>
#define rep(i, n) for (ll i = 0; i < n; ++i)
typedef long long ll;
using namespace std;
const int INF = 1e9;

int main() {
    int n;
    cin >> n;
    int now = 0;

    bool flag = true;
    rep(i, n) {
        int x;
        cin >> x;

        if (abs(x - now) != 1) {
            flag = false;
            break;
        }
        now = x;
    }

    flag ? cout << "T" : cout << "F";
    cout << endl;

    return 0;
}