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

Ex Input:
iMwanJBuMdiZDL, kIafHeBuMdiZmKNA

Ex Output:
BuMdiZ


Ex Input:
euQWhCovKplukMYznXcD, XAfMhKdzhCovKplukMcMlSuBw

Ex Output:
hCovKplukM


Ex Input:
OPuWOuXOOOzfsJ, qCFrsWOuXOOXoU

Ex Output:

WOuXOO