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

Q: NxgzLSzFGa, JvLzLSzsuj

A: zLSz
****
Q: QvtDqzQiSknPbRCG, hVxHdqzQiSknPbumdpNIf

A: qzQiSknPb
****
Q: xeKSiBafhOWBbYwlGaQ, GUfIsKgafhOWBbYiFWnptAt

A:
afhOWBbY
****