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

[Q]: MriFNpGM, yaiFNduk
[A]: iFN


[Q]: ssKUiWgGqsXYlFOOc, JDcVTmCgGqsXYlxYE
[A]: gGqsXYl


[Q]: Olojrdkvu, DNKjrdkQXBL
[A]:
jrdk