Palindromic Permutation Checker

Given a string s, check whether any permutation of s can form a palindrome. A string is a palindrome if it reads the same backward as forward. For a palindromic permutation to exist, at most one character can have an odd frequency.

Formally, let \( freq(c) \) be the frequency of character \( c \) in the string. A necessary and sufficient condition for the existence of a palindromic permutation is: \[ \text{Number of characters with } freq(c) \equiv 1 \pmod{2} \le 1 \]

The check is case-sensitive, meaning that uppercase and lowercase letters are considered different.

inputFormat

Input is provided via standard input. It contains a single line with a non-empty string s consisting of letters. The string may include both uppercase and lowercase characters.

outputFormat

Output a single integer to standard output. Print 1 if some permutation of s can form a palindrome, otherwise print 0.

## sample

aabb

1

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