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
$input = file_get_contents('php://stdin');
$inarr = explode("\n", $input);

$nmlist = explode(" ", $inarr[0]);
$aList = array_map("intval", explode(" ", $inarr[1]));

$n = (int)$nmlist[0];
$m = (int)$nmlist[1];

$sum = array_sum($aList);
$div = $sum/(4 * $m);

for($i=0;$i<$m;$i++){
    $select = max($aList);
    if($select<$div){
        echo "No"."\n";
        exit();
    }
    $aList = array_diff($aList, [$select]);
}
echo "Yes"."\n";

?>