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: atDgsOWuP, UJMgsOrwj

Answer: gsO


Question: aWshKwEuYBBdSwIAyXw, wfVuYBBdSwIAseTxR

Answer: uYBBdSwIA


Question: BibWPkUUHkvBK, fllPkUUHCbgps

Answer:
PkUUH