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

Ex Input:
sJRFPufsaWXNeu, AePufsafc

Ex Output:
Pufsa


Ex Input:
dsngGP, KvnglB

Ex Output:
ng


Ex Input:
iVImRZVSLQP, QSRZVSVjya

Ex Output:

RZVS