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: edjRAatlaiCmWkpqMh, qDZYVWCDTRAatlaiCmYH

A: RAatlaiCm
****
Q: YgDAGGbXdPFuKFyY, UKDzGbXdPFOYsdr

A:
GbXdPF
****