Problem:
Score : 400 points

Problem Statement

Given is a number sequence A of length N.

Find the number of integers i \left(1 \leq i \leq N\right) with the following property:

For every integer j \left(1 \leq j \leq N\right) such that i \neq j , A_j does not divide A_i.

Constraints

All values in input are integers.

1 \leq N \leq 2 \times 10^5

1 \leq A_i \leq 10^6

Input

Input is given from Standard Input in the following format:

N
A_1 A_2 \cdots A_N

Output

Print the answer.

Sample Input 1

5
24 11 8 3 16

Sample Output 1

3

The integers with the property are 2, 3, and 4.

Sample Input 2

4
5 5 5 5

Sample Output 2

0

Note that there can be multiple equal numbers.

Sample Input 3

10
33 18 45 28 8 19 89 86 2 4

Sample Output 3

5

Solution in OCaml (4.10.0) (judge verdict: Time Limit Exceeded)

open Batteries
module EnumL = Enum.Labels
module ListL = List.Labels
module ArrayL = Array.Labels

let dbg0 x = Printf.eprintf "[debug]%s\n" @@ dump x
let dbg1 x = dbg0 x; x

let id = identity

let (++) n m = if n >= m then [] else List.range n `To m
let (++-) n m = if n >= m then List.range n `Downto m else []
let (++^) n m = if n < m then List.range n `To (pred m) else []

module ModOp = struct
  let prime = 1_000_000_007
  let (-) a b = (a + prime - b) mod prime
  let (+) a b = (a + b) mod prime
  let ( * ) a b = (a * b) mod prime

  let rec pow x n =
    if n = 0 then 1
    else if n mod 2 = 0 then pow (x*x) (n/2)
    else x * pow (x*x) (n/2)
end

let scan fmt = Scanf.sscanf (read_line ()) fmt

let scan_lines n fmt f =
  if n = 0 then []
  else List.map (fun _ -> scan fmt f) (1 ++ n)

let scan_list ?sep cnv =
  let line = read_line () in
  (match sep with
   | None -> List.map String.of_char @@ String.to_list line
   | Some sep -> String.split_on_char sep line)
  |> List.map cnv

let scan_array ?sep cnv = Array.of_list @@ scan_list ?sep cnv

let scan_matrix n m e ?sep conv =
  let arr = Array.make_matrix n m e in
  ListL.iter (0 ++^ n)
    ~f:(fun i -> arr.(i) <- Array.of_list @@ scan_list ?sep conv);
  arr

let atoi c = Char.code c - Char.code '0'

let rec powerset = function
  | [] -> [[]]
  | hd::tl ->
    let pws =  powerset tl in
    pws @ ListL.map pws ~f:(fun pw -> hd::pw)

let permutations l =
  let rec interleave x = function
    | [] -> [[x]]
    | (hd::tl) as l ->
      (x::l) :: (interleave x tl |> ListL.map ~f:(fun l -> hd::l)) in
  let rec aux = function
    | [] -> [[]]
    | a::rest ->
      aux rest |> ListL.map ~f:(interleave a) |> List.concat in
  aux l

let intersection l =
  EnumL.filter ~f:(fun x -> EnumL.exists ~f:((=) x) @@ Enum.clone l)

let zip l m =
  let n = min (List.length l) (List.length m) in
  List.combine (List.take n l) (List.take n m)

let lower_bound n f =
  let rec aux l u =
    if u - l > 1 then
      let m = (l + u) / 2 in
      if f m then aux l m
      else aux m u
    else u in aux (-1) n

let between n x m = n <= x && x < m

let n = scan "%d" id
let ls = List.sort Int.compare @@ scan_list ~sep:' ' Int.of_string

let () =
  let hcount = Hashtbl.create n in
  ListL.iter ls ~f:(fun v -> Hashtbl.modify_def 0 v succ hcount);
  let h = Hashtbl.create n in
  ListL.fold_left ls ~init:0 ~f:(fun pred v ->
      let n = Hashtbl.find hcount v in
      if n >= 2 then (Hashtbl.modify_def true v id h; pred)
      else
        let rec aux i =
          if i * i > v then 1
          else if v mod i = 0 && (Hashtbl.mem h i || Hashtbl.mem h (v/i)) then 0
          else aux @@ succ i in
        let w = aux 1 in
        Hashtbl.modify_def true v id h; pred + w)
  |> Printf.printf "%d\n"