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

[EX Q]: txJhzNeBj, qLJhzNesV
[EX A]: JhzNe

[EX Q]: RyaNyUvXAaZHLXUtYuz, CkbsWxZyUvXAaZHLXJJzugDy
[EX A]: yUvXAaZHLX

[EX Q]: STgcjFvVBaw, WMjFvVdP
[EX A]:
jFvV