let get_int () = Scanf.scanf "%d " (fun v -> v)
let input_int_array n =
  Array.init n (fun _ -> Scanf.scanf "%d " (fun v -> v))

let () =
  let n = get_int ()
  in
  input_int_array n
  |> Array.to_list
  |> List.sort_uniq Pervasives.compare
  |> List.length
  |> Printf.printf "%d\n"


