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 Java (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;
public class Main {
    public static void main(String [] args){
        Scanner input = new Scanner(System.in);
       
        String w = input.next();
        int count = 0;
        for(int i = 0; i < w.length()/2; i++){
            //System.out.println(w.length()-(i+1));
            if(w.indexOf(i)== w.indexOf(w.length()-(i+1)))
                count+=1;
        }
        //System.out.println(count);
        if(count==w.length()/2)
            System.out.println("Yes");
        else
            System.out.println("No");
    }
}