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

DQBpdnwVDcnCDEWpD, gAtCdnwVDcnCYv
dnwVDcnC

lsNwypFwhKP, diEfLwypFwEKqCN
wypFw

DZIfjvpTeHVKtYEQm, wDdqyIfjvpTeHVKmBTFvTCTnk

IfjvpTeHVK