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

iYSNsY, HSSNhP
SN

egYXVtCPvWxP, VMOolyVtCPvWjIx
VtCPvW

hEhMfVbfBODZdAUKpN, uZGKbfBODZJcp

bfBODZ