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

Ex Input:
gXwuhXJrEdzGOmLSKdK, TohXJrEdzGavU

Ex Output:
hXJrEdzG


Ex Input:
mXHhaCEIwqwEZcz, JZPXbYHhaCEIwZmna

Ex Output:
HhaCEIw


Ex Input:
XKqLFztbJYOEo, wEonLFztbJLBvmjD

Ex Output:

LFztbJ