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

Q: tftBHoDOYxCoTHVf, qhHoDOYxfUU

A: HoDOYx
****
Q: rszjOPpbXm, pnBujOPpWHz

A: jOPp
****
Q: kgDSRmZYD, NrSRmZRWX

A:
SRmZ
****