#include <bits/stdc++.h>
#define int long long 
using namespace std;

signed main() {

int N;
cin >> N;

vector<int> A(N+1);
A.at(0) = 0;
for( int i = 1; i <= N; i++ ){
cin >> A.at(i);
if( abs(A.at(i) - A.at(i-1)) != 1 ){
cout << "F" << endl;
return 0;
}
}
cout << "T" << endl;

}