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]: fifpfppfii
[EX A]: fppf

[EX Q]: twwntwnnnttwnw
[EX A]: nnn

[EX Q]: ssssptptstppstp
[EX A]:
ptstp