instruction:
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.
question:
xghghxghxxhxg
answer:
hxxh


question:
yynnnyfnynyynyf
answer:
ynyyny


question:
dkdffkdkdk
answer:

kdkdk