import Data.List

isBeautifulString :: String -> String
isBeautifulString s
  | s == "" = "Yes"
  | mod (length s) 2 /= 0 = "No"
  | s!!0 /= s!!1 = "No"
  | otherwise = isBeautifulString $ drop 2 s

main = do
  s <- getLine
  putStrLn $ isBeautifulString $ sort s
