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

Ex Input:
xMxyohPBlJIEBqghiMdBQPwq, xsBlJIEBqghlMosK

Ex Output:
BlJIEBqgh


Ex Input:
uqazNuZhdJhw, KbnrzNuZhBdp

Ex Output:
zNuZh


Ex Input:
fIQLQZkYVRRw, TfQLQZkvmu

Ex Output:

QLQZk