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

[Q]: CuizrSvJTRWZK, udyrSvJTRZzkS
[A]: rSvJTR


[Q]: YWNPkA, LuNPnN
[A]: NP


[Q]: QYbLbORZkEjKxxb, hPLbORZkKqHRl
[A]:
LbORZk