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

[Q]: SUgXyznbUQRpiLUTlRb, jlnwLTnbUQRpioUFyJ
[A]: nbUQRpi


[Q]: CUxfOt, dyxfNp
[A]: xf


[Q]: KpyKIdmLMnxJwW, vwyKIdmLsuJyzI
[A]:
yKIdmL