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

sHndIbPaygfNvnquxIHeteW, huLmJWXZIgfNvnquxIViQDhbuoL
gfNvnquxI

cvZfWOwa, xOfWOhZs
fWO

eDhnBPwPmGwqzAKELfROOO, KiTfLSIumGwqzAKELxYIdUDM

mGwqzAKEL