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

[Q]: nxTtNYaazlOyEBApiUSJS, BLazlOyEBCV
[A]: azlOyEB


[Q]: ftvxfhsnJEygzV, JYxSfhsnJnIqkW
[A]: fhsnJ


[Q]: xvHDvRh, rkHHDves
[A]:
HDv