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

[Q]: wLLwjL, arLwXm
[A]: Lw


[Q]: wnIFoRQvMMKMAqpCQYncuWUTJs, bPMUKKxYRxQvMMKMAqpCmzAPPMD
[A]: QvMMKMAqpC


[Q]: EMykbOwNCUQBTZjcp, tQekbOwNCUQBThDE
[A]:
kbOwNCUQBT