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

RAmKlEAUfWcgF, ZlWfEAUfWvVRa
EAUfW

xQcYRVFFqrVAMsBm, VErcKZvcYRVFFqzKo
cYRVFFq

CzPvZzsNy, oUzzvZzsDc

vZzs