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 OCaml (4.02.3) (judge verdict: Wrong Answer)

let charl_of_string s =
  let rec exp i l =
    if i < 0 then l else exp (i - 1) (s.[i] :: l) in
  exp (String.length s - 1) []

let dp = Array.make 26 0

let calc c =
  let ind = (int_of_char 'a') - 97 in
  dp.(ind) <- dp.(ind) + 1

let flag = ref true
let cl =
  read_line ()
  |> charl_of_string
  |> List.map calc
  
let () =
  for i = 0 to 25 do
    if dp.(i) mod 2 = 1 then flag := false
  done;
  if !flag then print_endline "Yes"
  else print_endline "No"