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]: dddkdkdnknnk
[EX A]: dkdkd

[EX Q]: gggggxffggfxff
[EX A]: ggggg

[EX Q]: pnxnxnxxnnnpx
[EX A]:
nxnxn