Problem:
Score : 200 points

Problem Statement

Let w be a string consisting of lowercase letters.
We will call w beautiful if the following condition is satisfied:

Each lowercase letter of the English alphabet occurs even number of times in w.

You are given the string w. Determine if w is beautiful.

Constraints

1 \leq |w| \leq 100

w consists of lowercase letters (a-z).

Input

The input is given from Standard Input in the following format:

w

Output

Print Yes if w is beautiful. Print No otherwise.

Sample Input 1

abaccaba

Sample Output 1

Yes

a occurs four times, b occurs twice, c occurs twice and the other letters occur zero times.

Sample Input 2

hthth

Sample Output 2

No

Solution in Haskell (GHC 7.10.3) (judge verdict: Accepted)

import Control.Applicative
import Data.List

getInt :: IO Int
getInt = (\a -> read a :: Int) <$> getLine

getInteger :: IO Integer
getInteger = (\a -> read a :: Integer) <$> getLine

count :: String -> Bool
count "" = True
count [_] = False
count (x:y:xs)
    | x == y = count xs
    | otherwise = False

main = do
    putStrLn =<< (((\a -> if a then "Yes" else "No") . count . sort) <$> getLine)