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 Pascal (FPC 2.6.2) (judge verdict: Accepted)

var n, m, i, sum, val, cnt : longint;
    a : array[1..1000] of longint;
    
begin
    readln(n, m);
    sum := 0;
    for i := 1 to n do 
    begin
        read(a[i]);
        sum := sum + a[i];
    end;
    val := (sum + 4 * m - 1) div (4 * m);
    cnt := 0;
    for i := 1 to n do
    if (a[i] >= val) then inc(cnt);
    
    if (cnt < m) then writeln('No')
    else writeln('Yes');
end.