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

Ex Input:
CiElmOvTqJGVJkfSaDRzE, EjDJwMyxTvTqJGVJkfluB

Ex Output:
vTqJGVJkf


Ex Input:
oiNEYHxbvAb, bcDDdEYHxbCREd

Ex Output:
EYHxb


Ex Input:
OXHVrATj, JaHVrej

Ex Output:

HVr