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: sJRFPufsaWXNeu, AePufsafc

Answer: Pufsa


Question: RyaNyUvXAaZHLXUtYuz, CkbsWxZyUvXAaZHLXJJzugDy

Answer: yUvXAaZHLX


Question: BCLnQYNQiYrdW, WfYNQiYrnQxGnV

Answer:
YNQiYr