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 PHP7 (7.0.15) (judge verdict: Accepted)

<?php
/**
 * Created by PhpStorm.
 * User: wahho
 * Date: 2016/08/28
 * Time: 20:56
 */
fscanf(STDIN, "%s", $in_w);
$arr_w = array();
for($i = 0; $i < strlen($in_w); $i++){
    $arr_w[] = substr($in_w, $i, 1);
}
// echo "test: $arr_w[0] $arr_w[1] $arr_w[2]";
sort ($arr_w);

$ans_b = "Yes";
$kazu = 0;
$mae = "null";
foreach ($arr_w as $w){
//    echo "test: $ans_b $kazu $mae $w\n";
    if($mae == $w){
        $kazu++;
    }elseif(($kazu % 2) == 0){
        $mae = $w;
        $kazu = 1;
    }else{
//        $ans_b = "No";
        break;
    }
}
if(($kazu % 2) != 0){
    $ans_b = "No";
}

echo "$ans_b\n";
?>