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

rqhQxQQDdYwemFiiwcfVx, cEQDdYwemFtwpfNJC
QDdYwemF

sHndIbPaygfNvnquxIHeteW, huLmJWXZIgfNvnquxIViQDhbuoL
gfNvnquxI

hMyjjUcuHTFJfp, jggptFyjjUcuHjO

yjjUcuH