In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.

Q: gfDDsblwUryUw, UWaRisblwUTqTM

A: sblwU
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Q: JzbEpAquDJFKcNvEWZxVqRV, PFiJlpAquDJFKcNcqOpMeAv

A: pAquDJFKcN
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Q: KZQFBCuKzy, XulagFBCuKsOp

A:
FBCuK
****