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

DQBpdnwVDcnCDEWpD, gAtCdnwVDcnCYv
dnwVDcnC

gHFwDorPbNPORVgdLW, AfqDQvCGFwDorPbNPVPVmbQ
FwDorPbNP

llkdzBkvQYxgEzZpISWct, ZiQprZoYxgEzZpISWRuDRyedl

YxgEzZpISW