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

Example Input: OezHeoe, ouUzHemU
Example Output: zHe

Example Input: ocjsZZfSBBopDtgWUT, rWmgzsZZfSBBoGWQ
Example Output: sZZfSBBo

Example Input: yITbYie, TlqTbYomH
Example Output:
TbY