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: AuSFmN, crSFXM

A: SF
****
Q: elloYaejTczBiiNOU, XoCPzloYaejTcXYtKODL

A:
loYaejTc
****