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: RMurrwPjlfG, QBKrrwPDkTM

Answer: rrwP


Question: DwkTGsIXLfmjMV, VqRlMxtsSBkTGsIXLfmjbvI

Answer: kTGsIXLfmj


Question: JkDaxoRHkriLWnaKZlCD, TjilybvRHkriLWqqoFB

Answer:
RHkriLW