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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>

int comp(const void *px, const void *py){
    char x = *(char*)px;
    char y = *(char*)py;
    return (x>y)?1:(x<y)? -1:0;
}

int main(void){
    char w[101];
    int count[100];
    int yn=1;

    scanf("%s",w);
    if(strlen(w)%2==1){
        yn=0;
    }else{
        qsort(w,strlen(w),sizeof(char),comp);
        int i=0;
 
        while(w[i]<strlen(w)-1){
            //printf("1  ");
            int c=i+1;
            while(w[i]==w[c]){
                //printf("2  ");
                c++;
            }
            if(i/(c-1)%2==1){
                yn=0;
                break; //奇数検知
            }
            i=c;
        }

        if(yn==0){
            puts("No");
        } else{
            puts("Yes");
        }
        
    }
    return 0;

}