{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TupleSections #-}
import qualified Data.ByteString.Lazy.Char8 as B
import Data.Maybe
import Data.List
import Data.Bits
import qualified Data.IntSet as IS
import qualified Data.Vector.Unboxed as VU
import qualified Data.Vector.Unboxed.Mutable as VUM
-- import Control.Monad
-- import Control.Monad.ST
-- import Debug.Trace

solve :: Int -> [Int] -> Int
solve n as = answer
  where
  iset0 = IS.fromList as

  answer = sum $ unfoldr f iset0
    where
    f iset
      | IS.null iset = Nothing
      | IS.member x iset = Just (1, IS.delete x isetNxt)
      | otherwise        = Just (0, isetNxt)
      where (b, isetNxt) = IS.deleteFindMax iset
            x = btox b

btox b = setBit 0 (64 - (countLeadingZeros (b-1))) - b

readBInt :: B.ByteString -> Int
readBInt = fst . fromJust . B.readInt

tmain :: B.ByteString -> Int
tmain cont =
  let remLines0 = map B.words (B.lines cont)
      [bs_n]:remLines1 = remLines0
      n = readBInt bs_n
      line2:remLines2 = remLines1
      as = map readBInt line2
  in solve n as

outAnswer :: Int -> IO ()
outAnswer = putStrLn . show

main :: IO ()
main = outAnswer . tmain =<< B.getContents
