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

Ex Input:
bUcuzFgsdfojVR, IdcuzFgsdMRgtMA

Ex Output:
cuzFgsd


Ex Input:
BrDGrTD, PBHDGrDw

Ex Output:
DGr


Ex Input:
AmCXQMexXk, SbbCXQMeGHqZU

Ex Output:

CXQMe