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

[Q]: vSFxjd, AHFxpi
[A]: Fx


[Q]: bUcuzFgsdfojVR, IdcuzFgsdMRgtMA
[A]: cuzFgsd


[Q]: SoghmD, MAghtU
[A]:
gh