module M = Map.Make (struct
  type t = int
  let compare = (-)
end)

let read () = Scanf.scanf "%d " (fun i -> i)

let () =
  let n = read () in
  let rec doit i m =
    if i = n then m
    else
      let a = read () in
      doit (i + 1)
        (if not (M.mem a m) then M.add a 1 m else M.add a (M.find a m + 1) m) in
  let m = doit 0 M.empty in
  M.fold (fun _ n s -> s + if n = 1 then 1 else 0) m 0 |> Printf.printf "%d\n"