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

[Q]: TizkNtJUPHfhmGQ, enzehVkNtJUPHunpG
[A]: kNtJUPH


[Q]: YWNPkA, LuNPnN
[A]: NP


[Q]: nvKulVguIULBCsDrUnqMEek, GTeuVGwmeguIULBCsDcnaXjRaoJ
[A]:
guIULBCsD