Palindrome Reordering

You are given a string s consisting of lowercase letters and digits. Your task is to determine whether the characters of s can be rearranged to form a palindrome.

A string is a palindrome if it reads the same forwards and backwards. A necessary and sufficient condition for a string to be rearranged into a palindrome is that at most one character has an odd frequency count. In mathematical terms, if we let \( f(c) \) denote the frequency of character \( c \) in the string, then the string can be rearranged into a palindrome if and only if:

[ \sum_{c} \mathbf{1}_{{f(c) ;mod; 2 \neq 0}} \le 1 ]

Print YES if it is possible to reorder the string into a palindrome, otherwise print NO.

inputFormat

The input consists of a single line containing the string s composed of lowercase letters and digits.

outputFormat

Output a single line: YES if the string can be rearranged into a palindrome, and NO otherwise.

aabbcc

YES