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

[Q]: hRVyvwHqnN, geHeyvwHqiBiYJ
[A]: yvwHq


[Q]: sRTQgRgRUjEooapKdR, vzsBgRUjEooLBkYeH
[A]: gRUjEoo


[Q]: kqOUOezjqrIlIOh, YOGezjqrKG
[A]:
ezjqr