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

[Q]: ptVlCwpfOZIi, QEdyVlCwpfOwp
[A]: VlCwpfO


[Q]: FgQsxN, UMQsIa
[A]: Qs


[Q]: VpLJZMgLYkrJtnwPx, ePgLYkrJtUHtdSP
[A]:
gLYkrJt