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

Q: dsngGP, KvnglB

A: ng
****
Q: rqhQxQQDdYwemFiiwcfVx, cEQDdYwemFtwpfNJC

A: QDdYwemF
****
Q: SgHdqzEALWhumAYtFObOoO, SiWhumAYtFOxHLqzWouR

A:
WhumAYtFO
****