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

Q: yKtQOhYvrJVH, HQsTQOhYvPP

A: QOhYv
****
Q: pySBCdpe, AEBCdOR

A: BCd
****
Q: uKwDWyjTATZGCQIZENslCAdw, uLSUdWyjTATZGCQMZPbLEVz

A:
WyjTATZGCQ
****