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

[Q]: eNuawupVqQ, RIawuplUIf
[A]: awup


[Q]: wrVsKN, mOVsWo
[A]: Vs


[Q]: UDnJUxwIjWlZDLeYVRwDvD, JEvbRDvvwWlZDLeYVRwoOmGQyAz
[A]:
WlZDLeYVRw