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

Q: sRTQgRgRUjEooapKdR, vzsBgRUjEooLBkYeH

A: gRUjEoo
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Q: iaXeqfIrYKxPJRXxfSm, rIYKxPJRXxfsjVsqe

A: YKxPJRXxf
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Q: FQZXtHJWLwMpe, tBONGpJWUZXtHJWLwMfba

A:
ZXtHJWLwM
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