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

Q: CMrTXnTnTVaR, srnXnTnTDNULO

A: XnTnT
****
Q: wkVVZREWhcSCpvCTB, ZQWhcSCpvCDVUY

A: WhcSCpvC
****
Q: kfMlwxXM, fsrMlwJiy

A:
Mlw
****