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

pIkAtJHVcvzzZVz, btWerNSHVcvzzZTz
HVcvzzZ

ftvxfhsnJEygzV, JYxSfhsnJnIqkW
fhsnJ

tJSKZjrZiWUYqCkJNQ, lnUMKxiWUYqCkJnxgFzO

iWUYqCkJ