Palindrome sentence

mediumStrings20 XP

A sentence is a palindrome if it reads the same backwards once you keep only letters and digits and ignore upper/lower case. Return whether s is one.

Examples

Input: s = "A man, a plan, a canal: Panama"
Output: true
Input: s = "Hello"
Output: false

Examples use JSON: true/false/null are True/False/None in Python.