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

Ex Input:
PivhPfah, XSghPfOi

Ex Output:
hPf


Ex Input:
oZZUNCUHtIiauDxQ, OdindZUNCUHtIiLQmWJJf

Ex Output:
ZUNCUHtIi


Ex Input:
icMTRmqjWhGUyfQrlGWQwZKfPu, MsxhGUyfQrlGWFliKn

Ex Output:

hGUyfQrlGW