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

Ex Input:
uGDJixAmSiVaFRmfKRM, NsTGxsJixAmSiVageSw

Ex Output:
JixAmSiVa


Ex Input:
sJRFPufsaWXNeu, AePufsafc

Ex Output:
Pufsa


Ex Input:
wULiosYrQlfepCBQPs, FSYrQlfeaoPmC

Ex Output:

YrQlfe