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

[Q]: KfjqnJLciTXqkJK, yqfRcfqnJLcisSB
[A]: qnJLci


[Q]: OYERnjubLFovtcS, FngzQJVGERnjubLFafmzq
[A]: ERnjubLF


[Q]: EEPwbsGkDVDnUw, BJGkDVDnXlzwG
[A]:
GkDVDn