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

int main(){
  int t;
  cin>>t;
  int p[t];
  for(int i=0;i<t;i++){
    cin>>p[i];
    if(i==0){
      if(p[i]==1||p[i]==-1){
        continue;
      }
    }
    if(p[i]==p[i-1]+1 || p[i] == p[i-1]-1){
      continue;
    }
    else{
      cout<<"F"<<endl;
      return 0;
    }
  }
  cout<<"T"<<endl;
  return 0;
}