#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main() {
    int n;
    cin >> n;
    int pos = 0;
    while (n--) {
        int a;
        cin >> a;
        if (abs(pos-a) != 1) {
            puts("F");
            return 0;
        }
        pos = a;
    }
    puts("T");
    return 0;
}