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

Ex Input:
BeEgLISxThm, UGLISxEtP

Ex Output:
LISx


Ex Input:
JjEQVKijeyEQ, dwSVKijeywCTvb

Ex Output:
VKijey


Ex Input:
PKVgoIZBWQaSlRVzoyiS, MXUlqWQaSlRVzoxUGuGtUM

Ex Output:

WQaSlRVzo