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

TvNVpHLPYjBCeUpyxlzFZ, tgKdPKVYjBCeUpyPK
YjBCeUpy

XSnVeAjWLFWTgwmf, WsByLAjWLFWnQfl
AjWLFW

QjDQjzAIsnYgNmmetl, vyqDQjzAIsnNajYEheP

DQjzAIsn