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

RNYHvcNnbsUdJLvS, PpNnbsUdglWhl
NnbsUd

mmDhYqPJC, qThYqxW
hYq

okkNgCWYrVBgdDaSIZFD, mAgnVXyVBgdDaSIZIJvv

VBgdDaSIZ