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

Q: VRXUhOYfTul, JqZUhOYKq

A: UhOY
****
Q: CiTNsbepy, DFNsbeZl

A: Nsbe
****
Q: wvKnqxmcGHvENZIwIXD, PCDazyeZqxmcGHvENyRPTd

A:
qxmcGHvEN
****