#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>
#include <bitset>
#include <cassert>

using namespace std;

int main() {

    int T;
    cin >> T;
    int X;
    cin >> X;
    bool ok = true;
    for (int i = 1; i < T; ++i) {
        int Xi;
        cin >> Xi;
        if (X + 1 == Xi or X - 1 == Xi) {
            X = Xi;
        } else {
            ok = false;
        }
    }

    cout << (ok ? "T" : "F") << endl;

    return 0;
}