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]: xQcYRVFFqrVAMsBm, VErcKZvcYRVFFqzKo
[A]: cYRVFFq


[Q]: ZCNycjxzjvccU, hTWVjxzjvflVZY
[A]:
jxzjv