import Control.Applicative ((<$>))

import Data.ByteString.Char8 (ByteString)
import qualified Data.ByteString.Char8 as B

import Data.List (unfoldr)
import Data.List (foldl')

import Data.Char (isSpace)
import Data.Bits (xor)

import Data.IntSet (IntSet)
import qualified Data.IntSet as IS

main :: IO ()
main = do 
  getLine 
  solve <$> readil B.readInt <$> B.getLine >>= print
  
solve :: [Int] -> Int
solve = IS.size . foldl' f (IS.singleton 0)
  where f ns x | IS.notMember x ns = IS.foldl g ns ns
               | otherwise = ns
          where g s k = IS.insert (k `xor` x) s

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')