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

ykDpbd, YFDpmO
Dp

mOGzbnDXWnNurkBXtcqZ, NLahGzbnDXWnNYgMTOR
GzbnDXWnN

qaZjfKzDnXIFmICrQ, aNwDqKzDnXIFWKsEJ

KzDnXIF