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

[Q]: FiKGCRXutEOzMqP, xdxRXutEsl
[A]: RXutE


[Q]: iupYjFXrrMqWzJSLUSwmEukHc, hqajjWrrMqWzJSLnF
[A]: rrMqWzJSL


[Q]: rvLoiycpZw, idcvoiycpcLyD
[A]:
oiycp