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

[Q]: xQcYRVFFqrVAMsBm, VErcKZvcYRVFFqzKo
[A]: cYRVFFq


[Q]: GHdeqnuYnQ, zzQeqnutAZ
[A]: eqnu


[Q]: aEBoTIwJoEWCzVouvDAvDppQMLUh, TYSoEWCzVouvDuopsjt
[A]:
oEWCzVouvD