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

[Q]: BmwpAnWJ, klVwpAFw
[A]: wpA


[Q]: XHqQIPw, brqQIkAt
[A]: qQI


[Q]: ESpghgPbkRClKFygJh, XNSghgPbkRClKuPdMxC
[A]:
ghgPbkRClK