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 Python (3.4.3) (judge verdict: Accepted)

def can_vote(A, m):
    if m == 1:
        return True
    A.sort()
    total = sum(A)
    tt = total * (1/(4*m))
    
    counter = 0

    for i in range(len(A)-1, -1, -1):
        if A[i] >= tt:
            counter += 1
        else:
            break
    if counter >= m:
        return True
    else:
        return False

n, m = list(map(int, input().split()))
A = list(map(int, input().split()))
if can_vote(A, m):
    print("Yes")
else:
    print("No")