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

Q: qczzCr, zDzzUI

A: zz
****
Q: XMtSwZVAHsNYhbyDm, asAVAHsNYhSPuNLrV

A: VAHsNYh
****
Q: RxnklVyvBqRfNwbUybmve, gqnBVyvBqRfNwjlyYLie

A:
VyvBqRfNw
****