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

Q: TdvkBvVyJcSdYGGPfnyml, rIvIvVyJcSdYhtxG

A: vVyJcSdY
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Q: yRhCObvPZYoKUoQnyaatR, NHzLJYPZYoKUoQnJnIsZxC

A: PZYoKUoQn
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Q: biiwpi, Zwiwaj

A:
iw
****