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

Q: sOSXbnluNuvwMETKda, JzXbnluNuvyeVHO

A: XbnluNuv
****
Q: ZRjPgqbLL, uIsmPgqbBB

A: Pgqb
****
Q: UcxgLuURV, YDKkxgLuBl

A:
xgLu
****