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:
ttttunnnutn
answer:
tunnnut


question:
ggtrtgrrtrgr
answer:
gtrtg


question:
fffjjfjjffjfj
answer:

ffjjfjjff