In this task you will be given a string and you should find the longest substring that is a palindrome. A palindrome is a string that is the same backwards as it is forwards. If the shortest possible palindrome is length 1 you should return the first character.

Input: Consider Input: huuruuruuru

Output: uruuruuru


Input: Consider Input: bssssssbsbbsss

Output: bssssssb


Input: Consider Input: wsslsssssws


Output: sslss