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

module H = Hashtbl

let () =
  let n = read () in
  let tbl = H.create ~random:true n in
  let rec doit i =
    if i = n then ()
    else begin
      let a = read () in
      if not (H.mem tbl a) then H.replace tbl a 1
      else H.replace tbl a (H.find tbl a + 1);
      doit (i + 1)
    end in
  doit 0;
  H.fold (fun _ n s -> s + if n = 1 then 1 else 0) tbl 0 |> Printf.printf "%d\n"