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

Q: gwVLygvd, VOQLyglfo

A: Lyg
****
Q: XjYkMfARxWBSBjuXyDrFt, EtUxIfiHkMfARxWBSckTLTTnR

A: kMfARxWBS
****
Q: PrUpVztTsu, WQNUpVzfmw

A:
UpVz
****