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

[EX Q]: aWshKwEuYBBdSwIAyXw, wfVuYBBdSwIAseTxR
[EX A]: uYBBdSwIA

[EX Q]: TTagIJmzrOTdnKr, UONmtdHJmzrOTduWo
[EX A]: JmzrOTd

[EX Q]: jPXVCqtFM, fEuVCqSvN
[EX A]:
VCq