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 Ruby (2.3.3) (judge verdict: Wrong Answer)

n, a = gets.chomp.split(" ").map(&:to_i)
k = gets.chomp.split(" ").map(&:to_i)
j = k.sort.reverse
#p j
all = 0
(1..n).each do |i|
    all += k[i-1]
end
#puts all
count =0
#p all.to_i / (4 * a)
(0..a-1).each do |d|
    if j[d].to_i >= all.to_i / (4 * a)
        count += 1
    end
end
#p count
if a == count.to_i
    puts "Yes"
else
    puts "No"
end