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.

[Q]: nnnnyyunyuyyuny
[A]: nnnn


[Q]: isivssiivivvi
[A]: ivvi


[Q]: wxawxawxwwwxwa
[A]:
awxwwwxwa