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

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

[EX Q]: sdGIVJPsWWszKPCGk, ghRJPsWWszKcJUg
[EX A]: JPsWWszK

[EX Q]: nmhIhBlE, pJFhIhTed
[EX A]:
hIh