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

Ex Input:
EyvnjbVLF, vqnjblzR

Ex Output:
njb


Ex Input:
LJJvLTK, jpFJvLqh

Ex Output:
JvL


Ex Input:
xhHNKw, BAHNLY

Ex Output:

HN