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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

'use strict';
function main(input) {
  const a = input.trim().split('\n')[0].split(' ').map(x => Number(x));
  const b = input.trim().split('\n')[1].split(' ').map(x => Number(x)).sort(function (a, b) {
    return b - a;
  });
  let sum = 0;

  for (let i = 0; i < b.length; i ++) {
    sum += b[i];
  }

  if (b[(a[1] - 1)] < sum / 4 / (a[1] - 1)) {
    console.log('No');
  } else {
    console.log('Yes');
  }
  
}

main(require("fs").readFileSync("/dev/stdin", "utf8"));