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

Ex Input:
HKqfdEvqDuGhWByFlzIEeYh, VVaZfkLCMuGhWByFlzIOZaXbMCA

Ex Output:
uGhWByFlzI


Ex Input:
yywhNdZQkLSzbOvhluicHA, lfZQkLSzbOvhVC

Ex Output:
ZQkLSzbOvh


Ex Input:
tSJzlfCoIfmxVpiHgXy, iNpeWexszlfCoIfmYfbMEJ

Ex Output:

zlfCoIfm