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: rduIwWNGM, AJqYIwWNaCap

A: IwWN
****
Q: SYMYIaPwdHFBkRQDEOapcAbQQu, xsqoHFBkRQDEOaMAb

A:
HFBkRQDEOa
****