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:
qQkmYsYN, UhkmYHSy

Ex Output:
kmY


Ex Input:
uYpBnu, GLpBlZ

Ex Output:

pB