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

Ex Input:
txJhzNeBj, qLJhzNesV

Ex Output:
JhzNe


Ex Input:
wbdHVigIkjNkuAmbr, iSgIkjNkQYyn

Ex Output:
gIkjNk


Ex Input:
yXudpNEb, EsLdpNyPZ

Ex Output:

dpN