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

KKebLWQCQzVIojj, nxQCQzVIopD
QCQzVIo

srPyjmTQhdFFMcQ, QQGBdtyjmTQhmfEy
yjmTQh

ckevet, jZevyf

ev