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]: gxxxcccggxggccc
[EX A]: cccggxggccc

[EX Q]: kmmmmmkkmkm
[EX A]: kmmmmmk

[EX Q]: eoeoeeeoeeee
[EX A]:
eoeeeoe