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

AeYjeKwZQillzpD, SnqviKwZQillrxuTB
KwZQill

XMtSwZVAHsNYhbyDm, asAVAHsNYhSPuNLrV
VAHsNYh

PvXOjbhDGYFtfqebP, srYDGYFtfqeSsRHL

DGYFtfqe