let () =
  let n = read_int () in
  let s = Array.init n @@ fun _ -> Scanf.scanf "%s\n" @@ fun s -> s in
  let ans = Array.fold_left
      (fun (i,l) v -> if List.mem v l then (i,l) else (i+1, v :: l)) (0,[]) s in
  print_int (fst ans)