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

[Q]: andNlOdIcQMyZvc, vCMENolkslOdIcQMyZJtCFo
[A]: lOdIcQMyZ


[Q]: cKsJcqYvZO, UrsJcqBC
[A]: sJcq


[Q]: amtklD, bktkWN
[A]:
tk