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

[Q]: haOsaSQcyodWhqQaC, BKLEUQcyodWhvVkmxBz
[A]: QcyodWh


[Q]: RtOkkgLvhgfGlX, vCOkgLvhzOa
[A]: kgLvh


[Q]: npdOGFtcMfCBbnZCawHSwt, eRucKdOGFtcMfCBBya
[A]:
dOGFtcMfCB