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

[Q]: UZbmGVDzIaf, qfHwqGVDzIsd
[A]: GVDzI


[Q]: JXnHYuZvAYK, zhUYuZvASGhd
[A]: YuZvA


[Q]: FmMAcmbZBXShWsJl, DBoTnBbZBXShJfofgm
[A]:
bZBXSh