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

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    int T; cin >> T;
    vector<int> x = {0};
    rep(i,T) {
        int a; cin >> a;
        x.push_back(a);
    }

    int ok = 1;
    rep(i,T) ok &= abs(x[i] - x[i + 1]) == 1;
    cout << (ok ? "T" : "F") << endl;
}