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

Input: Consider Input: zBxuZfJgYrlRSzkmAktO, YNMgYrlRSzklmBOH

Output: gYrlRSzk


Input: Consider Input: HaIPcFXLhYDp, AdIPcFXtJdRE

Output: IPcFX


Input: Consider Input: gidhKXQFhvYPQL, MgKXQFhvYlxHty


Output: KXQFhvY