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 Ruby (2.3.3) (judge verdict: Wrong Answer)

w = gets.strip
count = {}
w.size.times{|i|
	count[w[i]] ||= 0
	count[w[i]] += 1
}

if count.map { |k,v|
	v % 2 == 0
}.all?
	puts "YES"
else
	puts "NO"
end