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 Fortran (gfortran v4.8.4) (judge verdict: Accepted)

program swap
  implicit none

  integer :: N, M
  integer :: i, j
  integer :: sum_vote
  real(kind=8) :: rate
  integer, allocatable :: A(:)

  read *, N, M

  allocate(A(1:N))
  read *, A(:)

  sum_vote = sum(A(:))
  rate = sum_vote * dble(4*M)**(-1)

  j = 0
  do i = 1, N
    if (A(i) >= rate) then
      j = j + 1
    end if
  end do

  if (j >= M) then
    print *, "Yes"
  else if (j < M) then
    print *, "No"
  end if
end program swap