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: ztgtzzzzzgzz

A: ztgtz
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Q: ushsuhsushuu

A: uhsushu
****
Q: nnnuuvnnuu

A:
nnn
****