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 abc161b
   implicit none
   integer :: m, n
   integer, allocatable ::  a(:), b(:)
   integer :: i
   real(8) :: m4

   read(*,*) n, m
   allocate(a(n), b(n))
   a(:) = 0
   b(:) = 0
   read(*,*) a(:)

   m4 = 1d0 / (4d0*m) * dble(sum(a))

   do i = 1, n
      if (m4 > a(i)) then
         b(i) = 0
      else
         b(i) = 1
      end if
   end do

   if (sum(b) >= M) then
      print *, "Yes"
   else
      print *, "No"
   end if

end program abc161b