Palindrome Verification

Given a string, determine whether it is a palindrome. A palindrome is a sequence of characters that reads the same forward and backward after removing all non-alphanumeric characters and ignoring case differences. In this problem, you are required to read input from standard input (stdin) and output the result to standard output (stdout).

Your program should output one of the following messages exactly:

• This is a palindrome.
• This is not a palindrome.

Note that an empty string is considered a palindrome.

inputFormat

The input consists of a single string which may include letters, numbers, spaces, punctuation, and other symbols. The entire string is provided via standard input (stdin).

outputFormat

Output exactly one line to standard output (stdout) with the following messages:

• If the input string is a palindrome: This is a palindrome.
• If the input string is not a palindrome: This is not a palindrome.

racecar

This is a palindrome.