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

[Q]: QKlzsmHyBcC, snPtzsmHdMIv
[A]: zsmH


[Q]: dxqZUOvRprXyFfjQfTWBhR, biSVjOvRprXyFfDtuFWQ
[A]: OvRprXyFf


[Q]: UkxpkhFNNX, LRjpkhFQpyq
[A]:
pkhF