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

Q: zbSNNVc, agSNNtOQ

A: SNN
****
Q: eJPZzg, lFPZbI

A: PZ
****
Q: WVXpRSHVPMYqSyAeyJ, btzRAtHVPMYqSyqyanNr

A:
HVPMYqSy
****