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

[Q]: EPUxsZtt, KgxsZuXM
[A]: xsZ


[Q]: uRLpAWCotLmxcSmKyvo, laotLmxcSmKyBwVfJB
[A]: otLmxcSmKy


[Q]: WknxuRayzdCKAeldksIwDnQXaK, DNaBzdCKAeldkMhY
[A]:
zdCKAeldk