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.

Q: puppppppppup

A: puppppppppup
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Q: ryzzyzzyyzz

A: yzzyzzy
****
Q: kknmnnkmkn

A:
nkmkn
****