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

[Q]: jXbgnl, lUbglP
[A]: bg


[Q]: TizkNtJUPHfhmGQ, enzehVkNtJUPHunpG
[A]: kNtJUPH


[Q]: QrRyaTsRPZCuOFBDnpIbeOp, nLCDOUPZCuOFBDwVHRLjnL
[A]:
PZCuOFBD