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

Input: Consider Input: PQCjJwXurLeN, vsjJwXuOy

Output: jJwXu


Input: Consider Input: jXbgnl, lUbglP

Output: bg


Input: Consider Input: vUFFzcHATeKlydFrGvjWvNKvvc, yFAEbDTTATeKlydFrGolIZQVpO


Output: ATeKlydFrG


