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

[Q]: BeEgLISxThm, UGLISxEtP
[A]: LISx


[Q]: PGjDRPDzGaBR, rpIJRPDzWi
[A]: RPDz


[Q]: FNVeaFmprNHqqtAaKv, iGBmrrMveaFmprNHqWWAvtht
[A]:
eaFmprNHq