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

Q: AxRSlkQfWHrdlgQG, iXIOrmlkQfWHTy

A: lkQfWH
****
Q: IGHhMfqLeBpnullsPInfBH, LTDBpnullsPIBynwCrCQ

A: BpnullsPI
****
Q: jVlwODm, uHhlwOBsr

A:
lwO
****