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

Example Input: andNlOdIcQMyZvc, vCMENolkslOdIcQMyZJtCFo
Example Output: lOdIcQMyZ

Example Input: ATmVEtUuZOgsBUuL, UMUuZOgsBPVT
Example Output: UuZOgsB

Example Input: rEyGCHxoirMexU, reyaCHxoiKns
Example Output:
CHxoi