import qualified Data.ByteString.Char8 as BS
import Data.Maybe

readString = map BS.unpack . BS.words

getString = readString <$> BS.getLine

check :: String -> String -> String
check [] as = as
check (s : ss) as = check ss as'
  where
    as'
      | s `elem` as = as
      | otherwise = s : as

main = do
  [s] <- getString
  if even ( length (check s "")) then putStrLn "Yes" else putStrLn "No"

