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

hRVyvwHqnN, geHeyvwHqiBiYJ
yvwHq

XbjDHRCWxdPbhibUKn, SrpuPDHRCWxdPbKPWEXNWbZ
DHRCWxdPb

sJdHanspwLZAF, aIQnspwLbhB

nspwL