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

eeoJEtGHPDvHck, ezPGHPDvHSf
GHPDvH

BVipiZoGXaWdjmDsxWP, yxppsiYkiZoGXaWdjoDRuKW
iZoGXaWdj

QDeLtiSprrV, qyHLtiStxo

LtiS