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

Q: HqaOvLaZbs, RifOvLaZkh

A: OvLaZ
****
Q: wDSKHtWbCDqTeoBeiYHdcZD, MydQCwqTeoBeiYHdYMp

A: qTeoBeiYHd
****
Q: Bdwxpj, QRwxIa

A:
wx
****