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

Ex Input:
oWwqraAz, uxTqraonu

Ex Output:
qra


Ex Input:
nxTtNYaazlOyEBApiUSJS, BLazlOyEBCV

Ex Output:
azlOyEB


Ex Input:
yeFFFfZNwEPbAMOd, gHxhauFfZNwEPbBJUG

Ex Output:

FfZNwEPb