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

BrDGrTD, PBHDGrDw
DGr

nrIHKzJCdAQzUDRBYpg, JDzJCdAQzUMMYrLcfO
zJCdAQzU

ytIybt, QyIyNa

Iy