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

[Q]: XYnCjAWPHHJ, gmCjAWPHpmwVsm
[A]: CjAWPH


[Q]: OUNqomxFcLXhWdfB, gdqomxFcLHQPCu
[A]: qomxFcL


[Q]: FQPztHeCxqkISfrm, pdOjSaHeCxqkQNhAt
[A]:
HeCxqk