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

[Q]: SQNzngllNbOkKDK, MijfNzngllNDfWge
[A]: NzngllN


[Q]: yKtQOhYvrJVH, HQsTQOhYvPP
[A]: QOhYv


[Q]: NtHxUcZUfDzcVrAH, dbgPAcZUfDzfhG
[A]:
cZUfDz