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

[Q]: VRXUhOYfTul, JqZUhOYKq
[A]: UhOY


[Q]: qMnjlfIsQRtUlPggCpHqu, gfVndMwYDIsQRtUlPgqBJKCX
[A]: IsQRtUlPg


[Q]: CvNzMDkk, FDzMDHE
[A]:
zMD