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:
ttvsvvvssst
answer:
svvvs


question:
zzzzyyyyzyzzzz
answer:
zyyyyz


question:
zzzzbbbzlzzb
answer:

zbbbz