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.

[EX Q]: ggjjggjkkjjkk
[EX A]: ggjjgg

[EX Q]: iwvivviivwvwiw
[EX A]: ivvi

[EX Q]: ylylzyzlzlzy
[EX A]:
yzlzlzy