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

[Q]: nYoRQU, gQoRZQ
[A]: oR


[Q]: wcJmSloqlddFOfv, szhUIAqzSloqlddFDJz
[A]: SloqlddF


[Q]: hActuTjabrmAnlvUCKovhvf, hQpuSmAnlvUCKovXSYcSGYcR
[A]:
mAnlvUCKov