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

Ex Input:
cjDuPZOHjystHnF, okWVdUDuPZOHjSCaEecP

Ex Output:
DuPZOHj


Ex Input:
sUdaWtsiRgqAYHykrHwjyDvZgD, MJdFXYiRgqAYHykrakSGHMr

Ex Output:
iRgqAYHykr


Ex Input:
hOVLdcCsOcvlwKaDYWeGUItHqSj, CLsOcvlwKaDYOMsezMaoz

Ex Output:

sOcvlwKaDY