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

[Q]: HhBhJMpxpty, MxTJMpxnQEf
[A]: JMpx


[Q]: eFUexDIFlaPDUwrOb, mTvkKGUxDIFlaPDUwxGVpnIwbi
[A]: xDIFlaPDUw


[Q]: iRTaDQXKXvJb, CNDQXKeA
[A]:
DQXK