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

Ex Input:
tftBHoDOYxCoTHVf, qhHoDOYxfUU

Ex Output:
HoDOYx


Ex Input:
uqazNuZhdJhw, KbnrzNuZhBdp

Ex Output:
zNuZh


Ex Input:
BywClSrHITeihJOmXP, cmmAYfwClSrHITVSHSyVM

Ex Output:

wClSrHIT


