import Control.Monad
import qualified Data.IntSet as S

main = do
  n <- readLn
  as <- map read <$> replicateM n getLine
  print . S.size $ solve S.empty as

solve s [] = s
solve s (a:as)
  | a `S.member` s = solve (S.delete a s) as
  | otherwise = solve (S.insert a s) as