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

PShMbsbexXGlpBuMMDZZS, sVqGxSexXGlpBxuHXoI
exXGlpB

srPyjmTQhdFFMcQ, QQGBdtyjmTQhmfEy
yjmTQh

WfsOofEUDItcOS, afHHpOofEUDCtK

OofEUD