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

OYERnjubLFovtcS, FngzQJVGERnjubLFafmzq
ERnjubLF

eeoJEtGHPDvHck, ezPGHPDvHSf
GHPDvH

zmfthgYv, KLfthgwd

fthg