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

Ex Input:
EJZYVxgFxPoOSDlLfK, uTLTIETHZYVxgFxPoPwr

Ex Output:
ZYVxgFxPo


Ex Input:
gXwuhXJrEdzGOmLSKdK, TohXJrEdzGavU

Ex Output:
hXJrEdzG


Ex Input:
INzkSU, jGzkxW

Ex Output:

zk