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:
yiyqiqyyiyyy
answer:
yqiqy


question:
pfppfvpppppff
answer:
ppppp


question:
xjxjjxjjjjjx
answer:

xjjjjjx