Problem:
Score : 200 points

Problem Statement

We have held a popularity poll for N items on sale. Item i received A_i votes.

From these N items, we will select M as popular items. However, we cannot select an item with less than \dfrac{1}{4M} of the total number of votes.

If M popular items can be selected, print Yes; otherwise, print No.

Constraints

1 \leq M \leq N \leq 100

1 \leq A_i \leq 1000

A_i are distinct.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N M
A_1 ... A_N

Output

If M popular items can be selected, print Yes; otherwise, print No.

Sample Input 1

4 1
5 4 2 1

Sample Output 1

Yes

There were 12 votes in total. The most popular item received 5 votes, and we can select it.

Sample Input 2

3 2
380 19 1

Sample Output 2

No

There were 400 votes in total. The second and third most popular items received less than \dfrac{1}{4\times 2} of the total number of votes, so we cannot select them. Thus, we cannot select two popular items.

Sample Input 3

12 3
4 56 78 901 2 345 67 890 123 45 6 789

Sample Output 3

Yes

Solution in OCaml (4.02.3) (judge verdict: Accepted)

open Printf
open Scanf

module L =
  struct
    include List
  
    let init n f =
      let rec loop x =
        if x = n then []
        else let y = f x in y :: loop (x + 1)
      in loop 0
  end

let id x = x

let solve n m =
  let l = L.init n @@ fun _ -> scanf "%d " id in
  let w = L.fold_left (+) 0 l in
  if m <= L.length (L.filter (fun x -> 4 * m * x >= w) l) then "Yes" else "No"

let () =
  scanf "%d %d " solve |> printf "%s\n"