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]: uvvvnnuunnvuu
[A]: vnnuunnv


[Q]: xrwxxxrrrxxxx
[A]: xxxrrrxxx


[Q]: qbbuqqubbbq
[A]:
bbuqqubb