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

RAmKlEAUfWcgF, ZlWfEAUfWvVRa
EAUfW

HSsyZzZLZAAq, MFEZzZLJC
ZzZL

FTiWUfbnFzrfrXb, pcUfbnFzrfrlVB

UfbnFzrfr