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

BmwpAnWJ, klVwpAFw
wpA

RGImMTISYdkjzMO, pmyfpImMTISYdatLBBFr
ImMTISYd

GQMUXkKDKBVJtyFQn, MCXtkKDKBVJtyToQuKy

kKDKBVJty