import Control.Applicative ((<$>), (<*>))
import Data.ByteString.Char8 (ByteString)
import qualified Data.ByteString.Char8 as B
import Data.List (unfoldr, foldl')
import Data.Char (isSpace)
import Data.IntMap (IntMap, (!))
import qualified Data.IntMap as IM

main :: IO ()
main = solve <$> f <*> f >>= print
  where f = readil B.readInt <$> B.getLine

solve :: [Int] -> [Int] -> Int
solve [n, x] as = IM.foldlWithKey' (\ct k v -> if IM.member (x-k) db then ct + v * db ! (x-k) else ct) 0 db
  where db = foldl' (\m a -> IM.insertWith (+) a 1 m) IM.empty as

readil :: Integral a =>  (ByteString -> Maybe (a, ByteString)) -> ByteString -> [a]
readil f = unfoldr g
  where g s = do
          (n, s') <- f s
          return (n, B.dropWhile isSpace s')