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: iaXeqfIrYKxPJRXxfSm, rIYKxPJRXxfsjVsqe

Answer: YKxPJRXxf


Question: CMrTXnTnTVaR, srnXnTnTDNULO

Answer: XnTnT


Question: BJFMzSocSGpvxXIk, UAmQmVCyocSGpvxXUNiRXp

Answer:
ocSGpvxX