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

[Q]: gfDDsblwUryUw, UWaRisblwUTqTM
[A]: sblwU


[Q]: PQSFjlnU, kTSFjMUh
[A]: SFj


[Q]: uUEGnoccQieiIbEjdUoYuvRF, nIrioGZIQieiIbEjVE
[A]:
QieiIbEj