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

[EX Q]: aZcGMvzBhazkCIFqpVe, AOljBvzBhazkWXeTuA
[EX A]: vzBhazk

[EX Q]: HorIyjpfBFmKZQUIEoP, AcWOaOgVPmyjpfBFmKZQPFYiI
[EX A]: yjpfBFmKZQ

[EX Q]: LhDGeTmxvEcZLlmIw, kmVDQXxvEcZLlHj
[EX A]:
xvEcZLl