Given a string, determine if it is a palindrome, considering only alphanumeric characters.

Palindrome

A palindrome is a word, number, phrase, or other sequences of characters which read the same backwards and forwards.

Example:

If the input string happens to be, "malayalam" then as we see that this word can be read the same as forward and backwards, it is said to be a valid palindrome.

The expected output for this example will print, 'true'.

From that being said, you are required to return a boolean value from the function that has been asked to implement.

Input Format:

The first and only line of input contains a string without any leading and trailing spaces. All the characters in the string would be in lower case.

Output Format:

The only line of output prints either 'true' or 'false'.

Note:

You are not required to print anything. It has already been taken care of.

Constraints:

0 <= N <= 10^6
Where N is the length of the input string.

Time Limit: 1 second