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

Ex Input:
CCzKRbuEAmN, qTLzKRbuhEqq

Ex Output:
zKRbu


Ex Input:
VTwtMVKmrRvL, WLoVtWtMVKmrDCke

Ex Output:
tMVKmr


Ex Input:
ydIEro, gVIEdi

Ex Output:

IE