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

Ex Input:
TUAHhdvHIBxogI, LjfGsAHhdvHJcSdNV

Ex Output:
AHhdvH


Ex Input:
nuwMzarLqoPvabJla, JKcrLqoPvabJNDCILGQ

Ex Output:
rLqoPvabJ


Ex Input:
DSyHXkqB, lHHXkkBN

Ex Output:

HXk