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

[Q]: jeQzwP, kSQzxq
[A]: Qz


[Q]: uHGHiARtdJbuG, OdZmiARtdrhC
[A]: iARtd


[Q]: jxiraD, zXirOR
[A]:
ir