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: nFgMXUzpStDAybiwm, aNJrXUzpStDjp

Answer: XUzpStD


Question: OVZxWYzAAxG, rStOxWYzJeoC

Answer: xWYz


Question: RkPFux, GLPFAy

Answer:
PF