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 PHP7 (7.0.15) (judge verdict: Accepted)

<?php
$n = 0;
$m = 0;
fscanf(STDIN, '%u %u', $n, $m);
$input = fgets(STDIN);

$votes = explode(' ', trim($input));
$total_votes = array_sum($votes);
$min_votes = (float)$total_votes / (float)(4 * $m);
$popular = 0;
foreach ($votes as $vote) {
	if ($vote >= $min_votes) {
		$popular++;
	}
	if ($popular >= $m) {
		echo "Yes";
		exit;
	}
}
echo 'No';