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

Q: ZhHtTXaUmsQfUMNrnt, KvvebSXaUmsQfBspwM

A: XaUmsQf
****
Q: JAfPtjqqUYMD, cpXItjqqFN

A: tjqq
****
Q: AthUlJooHNDCdZkezZxvhVpP, mUweClQHNDCdZkeYKoBHyo

A:
HNDCdZke
****