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

Q: OhMVLbQhBxEaOZY, iDVLbQhBxBiiD

A: VLbQhBx
****
Q: GBTHKtWUzK, ovVNKtWUmVJF

A: KtWU
****
Q: sonYoQwfjh, ojlnYoQiNM

A:
nYoQ
****