Palindrome Rearrangement

You are given a string s. Your task is to determine whether any permutation of s can form a palindrome. A palindrome is a string that reads the same backward as forward. For example, the string civic is a palindrome and ivicc can be rearranged to civic which is a palindrome, while hello cannot be rearranged to form any palindrome.

The necessary and sufficient condition for a string to be rearranged into a palindrome is that at most one character appears an odd number of times. Use this property to decide your answer.

Mathematically, let ( f(c) ) denote the frequency of character ( c ) in the string, then the string is palindromic rearrangable if and only if [ \sum_{c} \Bigl[ f(c) \mod 2 \Bigr] \le 1. ]

inputFormat

Input consists of a single line containing the string s. The string will consist of lowercase English letters only.

outputFormat

Output a single line containing either YES or NO. Output YES if the string can be rearranged into a palindrome, and NO otherwise.## sample

civic

YES