Valid Palindrome Checker

You are given a string that may contain letters, digits, punctuation, and spaces. Your task is to determine if the string is a valid palindrome after removing all non-alphanumeric characters and ignoring letter case differences. Note that an empty string is considered a palindrome. The check should also work correctly with Unicode characters.

In mathematical terms, given a string \( s \), let \( \tilde{s} \) be the string obtained by removing all non-alphanumeric characters from \( s \) and converting all letters to lower case. The string is a palindrome if \( \tilde{s} = \tilde{s}^{R} \), where \( \tilde{s}^{R} \) is the reverse of \( \tilde{s} \).

For example, when \( s = \texttt{\"A man, a plan, a canal: Panama\"} \), after processing we get \( \tilde{s} = \texttt{\"amanaplanacanalpanama\"} \) which is the same forwards and backwards, so the output should be True.

inputFormat

The input consists of a single line which contains the string \( s \). The string may include spaces, punctuation, and Unicode characters.

outputFormat

Output a single line: True if the processed string is a palindrome, or False otherwise.

A man, a plan, a canal: Panama

True