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: Wrong Answer)

<?php
list($item_count, $popular_item_count) = explode(' ', trim(fgets(STDIN)));
$array = explode(' ', trim(fgets(STDIN)));
// 得票数を降順に並べ替える
rsort($array);
// 全得票数を計算
$amount = 0;
foreach ($array as $num) {
  	var_dump($num);
    $amount += (int)$num;
}

$check = floor($amount / (4 * (int)$popular_item_count));
var_dump($amount);
$i = 0;
while ($i < (int)$popular_item_count) {
    if ((int)$array[$i] > (int)$check) {
        $output_array[] = $array[$i];
    }
    $i++;
}

if ((int)$popular_item_count === count($output_array)) {
    echo 'Yes';
} else {
    echo 'No';
}