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

wNiHcaiUPHnjp, aSTmjcaiUPHFzOu
caiUPH

DhhYhrqVMXSoyvXQwqPKzWARAP, CaMXSoyvXQwqcDDtMsVqD
MXSoyvXQwq

yBQJdA, RIQJOC

QJ