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 Haskell (GHC 7.10.3) (judge verdict: Wrong Answer)

threshold :: Int -> [Int] -> Float
threshold m as = (fromIntegral . sum $ as) / (4.0 * fromIntegral m) 

point :: Int -> [Int] -> Int -> Int
point m as a = if fromIntegral a > threshold m as then 1 else 0

selectedCount :: Int -> [Int] -> Int
selectedCount m as = foldl1 ((+) . point m as) as

result :: Int -> [Int] -> String
result m as = if m <= selectedCount m as then "Yes" else "No"

{--
testprint :: Int -> Int -> [Int] -> IO ()
testprint n m as = do
     putStrLn $ "input " ++ show n ++ " " ++ show m ++ " " ++ show as
     putStrLn $ "threshold " ++ (show $ threshold m as) 
     putStrLn $ "selectedCount " ++ (show $ selectedCount m as)
     putStrLn $ "result " ++ result m as
--}

main :: IO ()
main = do

    [n, m] <- map read . words <$> getLine :: IO [Int]
    as <- map read . words <$> getLine :: IO [Int]
    let as' = take n as 
    putStrLn $ result m as'

    {--
    testprint 4 1 [5,4,2,1]
    testprint 3 2 [380,19,1]
    testprint 12 3 [4,56,78,901,2,345,67,890,123,45,6,789]
    --}