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

[Q]: VutZiVkDQcVpQO, BDQVDyBdiVkDQcVpuvNN
[A]: iVkDQcVp


[Q]: qQkmYsYN, UhkmYHSy
[A]: kmY


[Q]: yYtRpckwOnbF, cPtRpckwEYq
[A]:
tRpckw