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: LJJvLTK, jpFJvLqh

Answer: JvL


Question: RMurrwPjlfG, QBKrrwPDkTM

Answer: rrwP


Question: ZpRmEi, dhRmot

Answer:
Rm