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

Ex Input:
ATmVEtUuZOgsBUuL, UMUuZOgsBPVT

Ex Output:
UuZOgsB


Ex Input:
zgJGhxLU, EwJGhedW

Ex Output:
JGh


Ex Input:
WrNMdn, fzNMeo

Ex Output:

NM