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

[Q]: ptVlCwpfOZIi, QEdyVlCwpfOwp
[A]: VlCwpfO


[Q]: ftvxfhsnJEygzV, JYxSfhsnJnIqkW
[A]: fhsnJ


[Q]: bpfQbUuk, glQbUfQ
[A]:
QbU