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

Ex Input:
OBzHWjmkcgVGPyv, gCHWjmkcgVMq

Ex Output:
HWjmkcgV


Ex Input:
nFgMXUzpStDAybiwm, aNJrXUzpStDjp

Ex Output:
XUzpStD


Ex Input:
JmicAGmd, urEicAGKKm

Ex Output:

icAG