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: RNYHvcNnbsUdJLvS, PpNnbsUdglWhl

Answer: NnbsUd


Question: zbSNNVc, agSNNtOQ

Answer: SNN


Question: WUwHEBfSnDCWMX, aUlQEBfSnDCWRgqVUe

Answer:
EBfSnDCW