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

Q: uqazNuZhdJhw, KbnrzNuZhBdp

A: zNuZh
****
Q: hcmMoVBhK, mdmMoVBjuT

A: mMoVB
****
Q: MqMIVmbG, uAMIVYXu

A:
MIV
****