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

Ex Input:
LudFxiaqbX, UWMPnFxiaqikiDx

Ex Output:
Fxiaq


Ex Input:
OUNqomxFcLXhWdfB, gdqomxFcLHQPCu

Ex Output:
qomxFcL


Ex Input:
inXSTakkBOUWEKlzyrvy, ouDszQPzSTakkBOUWEzqOi

Ex Output:

STakkBOUWE