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: Accepted)

w = gets.chomp.split('').map(&:to_s)

def f(str, arr)
    len = arr.reduce(1) do |memo, item|
        item == str ? memo + 1 : memo
    end
    if(len%2 == 0) 
        arr = arr.select do |item|
            item != str
        end
        return arr.length == 0 ? true : f(arr.shift, arr)
    else 
        return false
    end
end

puts f(w.shift, w) ? "Yes" : "No"