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

[Q]: DwkTGsIXLfmjMV, VqRlMxtsSBkTGsIXLfmjbvI
[A]: kTGsIXLfmj


[Q]: cvZfWOwa, xOfWOhZs
[A]: fWO


[Q]: USHeBjupsAqvzldXugDbOIW, hyWhsUMbhsAqvzldXugYlhO
[A]:
sAqvzldXug