Rearrange to Palindrome

Given a string s consisting of lowercase alphabetical characters, determine if the characters of s can be rearranged to form a palindrome.

A string can be rearranged into a palindrome if at most one character has an odd frequency. In mathematical terms, let \( f(c) \) be the frequency of character \( c \) in the string. Then the string can form a palindrome if and only if

$$\sum_{c\in\text{alphabet}} \mathbb{1}_{\{f(c)\;\%\;2\neq 0\}} \leq 1$$

For example, the string "racecar" can be rearranged to form a palindrome, while "hello" cannot.

inputFormat

The input consists of a single line containing a string s of lowercase alphabetical characters. The string may be empty.

outputFormat

Output a single line: True if the string can be rearranged to form a palindrome, and False otherwise.## sample

racecar

True