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: XwBMFIV, SNLBMFZQ

Answer: BMF


Question: NwmTIZSnlKGG, qAYIZSnfWRd

Answer: IZSn


Question: dDtxKJeIsiZLqLN, QGucaJeIsiZBzncsZ

Answer:
JeIsiZ