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

Ex Input:
XMtSwZVAHsNYhbyDm, asAVAHsNYhSPuNLrV

Ex Output:
VAHsNYh


Ex Input:
nYoRQU, gQoRZQ

Ex Output:
oR


Ex Input:
FOWolXAzwKZX, rZDGzXAzwKAue

Ex Output:

XAzwK