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

FgQsxN, UMQsIa
Qs

dZJWBGoeoMepPoTg, pekBGoeoMeQP
BGoeoMe

NfiLHEDZmwzRPSZrYzTVc, cOEDZmwzRPIa

EDZmwzRP