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

[Q]: NwmTIZSnlKGG, qAYIZSnfWRd
[A]: IZSn


[Q]: pJqqIW, Ivqqxw
[A]: qq


[Q]: IkrasNNPtiRAFTU, GkTPXSsNNPtiglwpP
[A]:
sNNPti