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

Ex Input:
PzXzvmYrlGZgOBk, iKnzvmYrlGZgOrs

Ex Output:
zvmYrlGZgO


Ex Input:
cvRdSsuNwGVEwSSrowDpaOu, gFMcLKIeLwNwGVEwSSroUGskaoloqC

Ex Output:
NwGVEwSSro


Ex Input:
tAhWdyRqV, DNuWdylIE

Ex Output:

Wdy


