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

Example Input: oZZUNCUHtIiauDxQ, OdindZUNCUHtIiLQmWJJf
Example Output: ZUNCUHtIi

Example Input: HiEuutntEBpU, fdkqEuutntEBABdGZRND
Example Output: EuutntEB

Example Input: kIvhCcTgr, ZBvhCcYk
Example Output:
vhCc