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

Ex Input:
JAfPtjqqUYMD, cpXItjqqFN

Ex Output:
tjqq


Ex Input:
wnIFoRQvMMKMAqpCQYncuWUTJs, bPMUKKxYRxQvMMKMAqpCmzAPPMD

Ex Output:
QvMMKMAqpC


Ex Input:
dRtOLwHiSlFNLwAOHzlqew, JfmmvfzLwHiSlFNLwBBVk

Ex Output:

LwHiSlFNLw