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

[Q]: mRVieYomZqJXaTDsShCyfPW, ifOAlnptmZqJXaTDsVMqY
[A]: mZqJXaTDs


[Q]: DZfOjrQffR, CXOjrQQc
[A]: OjrQ


[Q]: tftBHoDOYxCoTHVf, qhHoDOYxfUU
[A]:
HoDOYx