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

Q: DhhYhrqVMXSoyvXQwqPKzWARAP, CaMXSoyvXQwqcDDtMsVqD

A: MXSoyvXQwq
****
Q: OXdSmcKG, XbDdSmJl

A: dSm
****
Q: deIhqgWZDHhSvnaudrFkiklbg, CEnHhSvnaudrlyrVt

A:
HhSvnaudr
****