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

Ex Input:
JKZiYILNeNQbJyznES, PHKILNeNQbJylltYH

Ex Output:
ILNeNQbJy


Ex Input:
ztkWLUJQXxP, fYluOkWLUJKDX

Ex Output:
kWLUJ


Ex Input:
XRZjQlSvvRmgrEqsvbnXu, oANuYpTSvvRmgrEqJrtK

Ex Output:

SvvRmgrEq