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

ocjsZZfSBBopDtgWUT, rWmgzsZZfSBBoGWQ
sZZfSBBo

TvNVpHLPYjBCeUpyxlzFZ, tgKdPKVYjBCeUpyPK
YjBCeUpy

PQaNTPePLQJYAmKvW, vKQBSpIxONTPePLQJYAWQkSyrlm

NTPePLQJYA