#include<bits/stdc++.h>
#define rep(i,a,n) for (int i = a;i < n;i++)
#define per(i,n,a) for (int i = n-1;i >= a;i--)
using namespace std;

int main() {
    int t;
    cin >> t;
    int x[999] = {};
    rep(i, 1, t + 1) {
        cin >> x[i];
    }
    rep(i, 1, t + 1) {
        if (abs(x[i - 1] - x[i]) != 1) {
            cout << 'F' << endl;
            return 0;
        }
    }
    cout << 'T' << endl;
}