Taco Palindrome Checker

This problem requires you to determine whether a given string is a palindrome. A string is considered a palindrome if it reads the same backward as forward when considering only alphanumeric characters and ignoring case. More formally, for a string \( s \), after removing all characters that are not letters or digits and converting all letters to lowercase, the string must satisfy:

\( s = s^R \)

where \( s^R \) is the reverse of \( s \). You are required to process multiple input strings and output "true" if a string is a palindrome and "false" otherwise.

inputFormat

The input is read from stdin and consists of several lines, each line representing one test case. Each line contains a string that may include letters, digits, spaces, punctuation, and other characters.

outputFormat

For each input line, output a single line to stdout containing either "true" if the input string is a palindrome or "false" otherwise.

## sample

A man, a plan, a canal, Panama
race a car
No lemon, no melon

true
false
true

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