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

RwduMBkDazrwZP, UPzcwtWMBkDazrAw
MBkDazr

PzXzvmYrlGZgOBk, iKnzvmYrlGZgOrs
zvmYrlGZgO

ZpevQNqIsBIvGixBOToy, LfleFxhHevQNqIsBIvyFGmUiUm

evQNqIsBIv