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

[Q]: yQCDWefwvrPP, RwoMDWefwhSxTR
[A]: DWefw


[Q]: ssKUiWgGqsXYlFOOc, JDcVTmCgGqsXYlxYE
[A]: gGqsXYl


[Q]: qNqnxMOiPLZWxbWQ, EzVIMOiPLZWxbnLFmd
[A]:
MOiPLZWxb