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:
ssnjnjssjnnn
answer:
njssjn


question:
llbklklkblkb
answer:
lbklklkbl


question:
exxfxefexxf
answer:

xefex