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

TdvkBvVyJcSdYGGPfnyml, rIvIvVyJcSdYhtxG
vVyJcSdY

LudFxiaqbX, UWMPnFxiaqikiDx
Fxiaq

vqLbPYavB, vMLbPYIp

LbPY