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

[Q]: YRNpKFPGzUsgCOBJgbVG, TdEpMngFPGzUsgCOZykYRrLp
[A]: FPGzUsgCO


[Q]: YcgVJVACcQE, JsJVACcSz
[A]: JVACc


[Q]: srPyjmTQhdFFMcQ, QQGBdtyjmTQhmfEy
[A]:
yjmTQh