In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
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Question: SFQHJlK, dHfQHJoUC

Answer: QHJ


Question: yQCDWefwvrPP, RwoMDWefwhSxTR

Answer: DWefw


Question: HgmgkGUDqmybaWJBAkanZuAah, vcWaWUewDqmybaWJBAhjCttOKpeY

Answer:
DqmybaWJBA