#include<iostream>
#include<vector>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<string>
#include<sstream>
#include<cmath>
#include<numeric>
#include<map>
#include<stack>
#include<queue>
using namespace std;
int mod = 1e9+7;

int main() {
  int t;cin >> t;
  vector<int> x(t);
  cin >> x[0];
  for(int i=1; i<t; i++){
    cin >> x[i];
    if( abs(x[i]-x[i-1]) != 1 ){
      cout << "F" << endl;
      return 0;
    }
  }
  cout << "T" << endl;
  return 0;
}

// EOF