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:
nxoonnnoonnooxo
answer:
oonnnoo


question:
iqpqipippqiiiq
answer:
iqpqi


question:
nznpnznznnpppnn
answer:

nznpnzn