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

Ex Input:
TWVTGNBh, nEVTGWq

Ex Output:
VTG


Ex Input:
cZSEmdgP, YsSEmEIM

Ex Output:
SEm


Ex Input:
SWVnYxxdu, UKnYxLB

Ex Output:

nYx