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:
pucuppppupu
answer:
uppppu


question:
qvvqvpvvqvvvq
answer:
vvqvv


question:
kmkmpmpkmkmkk
answer:

kmkmk