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: plSfJAktMfac, TCjYJAktlt

Answer: JAkt

Question: xfZYYDKEqoRRu, ztCeYYDKEqoPG

Answer: YYDKEqo

Question: UOYeIGW, BTkYeImS

Answer:
YeI