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]: vmmtvvttmvmvttv
[EX A]: tvvt

[EX Q]: nnnnyyunyuyyuny
[EX A]: nnnn

[EX Q]: hnhrnrnrrr
[EX A]:
rnrnr