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

int main(){
  int n;
  cin >> n;
  int x=0,y;
  for(int i=0;i<n;i++){
    cin >>y;
    if(abs(x-y)!=1){
      cout << "F" << endl;
      return 0;
    }
    x=y;
  }
  cout << "T" << endl;
  return 0;
}