#include <bits/stdc++.h>
using namespace std;
int main(){
    int T; cin >> T;
    vector<int> X;
    for(int i=0; i < T; i++){
        int x; cin >>x;
        X.push_back(x);
    }
    if(T == 1) cout << "F" << endl;
    for(int i=0; i < T - 1; i++){
        if(abs(X[i] - X[i+1]) != 1){
            cout << "F" << endl;
            return 0;
        }
    }
    cout << "T" << endl;
}