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 popular_vote
  implicit none
  integer :: n, m, i
  real(8) :: a(100) = 0.d0, x
  read(*,*) n, m
  read(*,*) a(1:n)
  x = sum(a(1:n))/(4.d0*m)
  do i = 1, n
    if (a(i) >= x) m = m-1
  end do
  if (m > 0) then
    write(*,'(a)') "No"
  else
    write(*,'(a)') "Yes"
  end if
end program popular_vote