TASK DEFINITION: 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.
PROBLEM: pbbbpxxxbxbb

SOLUTION: pbbbp

PROBLEM: gnfnggnfgngfgn

SOLUTION: fnggnf

PROBLEM: zmzmkkmzzzz

SOLUTION:
zmkkmz