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

wDSKHtWbCDqTeoBeiYHdcZD, MydQCwqTeoBeiYHdYMp
qTeoBeiYHd

rqhQxQQDdYwemFiiwcfVx, cEQDdYwemFtwpfNJC
QDdYwemF

ZJkPCZGUxuPzwbJb, FwBZGUxuPzooBF

ZGUxuPz