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

[Q]: Owbiay, exbime
[A]: bi


[Q]: mXHhaCEIwqwEZcz, JZPXbYHhaCEIwZmna
[A]: HhaCEIw


[Q]: eDmWiAFI, AyvWiALrj
[A]:
WiA