import Data.List
import Data.Array
import Data.Maybe
import qualified Data.ByteString as BS
import qualified Data.ByteString.Char8 as BS8
 
getInts :: IO [Int]
getInts = (map parseInt . BS8.words) <$> BS.getLine 
    where parseInt = fst . fromJust . BS8.readInt

cache :: (Int -> a) -> [a]
cache f = map f [0..]

cache2 :: (Int -> Int -> a) -> [[a]]
cache2 f = fmap cache (cache f)

memo :: (Int -> a) -> (Int -> a)
memo f = (cached !!)
    where cached = cache f

-- cache2 :: (Int -> Int -> a) -> [[a]]
-- cache2 f = map (\x -> map (f x) [0..]) [0..]

memo2 :: (Int -> Int -> a) -> (Int -> Int -> a)
memo2 f = (\x y -> cached !! x !! y)
    where cached = cache2 f

cache3 :: (Int -> Int -> Int -> a) -> [[[a]]]
cache3 f = fmap cache2 (cache f)

memo3 :: (Int -> Int -> Int -> a) -> (Int -> Int -> Int -> a)
memo3 f = (\x y z -> cached !! x !! y !! z)
    where cached = cache3 f

-- memo example
{-- 
fastfibo :: Int -> Integer
fastfibo = memo fibo

fibo :: Int -> Integer
fibo 0 = 0
fibo 1 = 1
fibo n = fastfibo (n-1) + fastfibo (n-2)
--}

 
solve :: [Int] -> Int -> Integer
solve arr a = sum $ map f [1..n]
    where n = length arr
          f cnt = f' 0 cnt (cnt*a)
          f' idx cnt s
            | idx == n && (cnt == 0 && s == 0) = 1
            | idx == n = 0
            | otherwise = f'' (idx+1) cnt s + f'' (idx+1) (cnt-1) (s-(arr !! idx))
          f'' idx cnt s 
            | cnt < 0 || s < 0 = 0
            | otherwise = (memo3 f') idx cnt s

main :: IO ()
main = do
    [n, a] <- getInts
    arr <- getInts
    print (solve arr a)