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

Q: KJswoapnXz, EQswoaFyH

A: swoa
****
Q: YWNPkA, LuNPnN

A: NP
****
Q: IvETGnTtNlVPuPgJhZElSJq, GyFMiuZtNlVPuPgPVepMDh

A:
tNlVPuPg
****