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

QjDQjzAIsnYgNmmetl, vyqDQjzAIsnNajYEheP
DQjzAIsn

yQCDWefwvrPP, RwoMDWefwhSxTR
DWefw

OrbvVjipPnnHhNTfm, JzVNIFjDjipPnnHhNTcVsYVP

jipPnnHhNT