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

Ex Input:
jinzsW, SMnzaW

Ex Output:
nz


Ex Input:
LJJvLTK, jpFJvLqh

Ex Output:
JvL


Ex Input:
XzvYQzsiTj, AdkQevYQzsNL

Ex Output:

vYQzs