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

aZcGMvzBhazkCIFqpVe, AOljBvzBhazkWXeTuA
vzBhazk

nhGinCtvLartcMPhJwGRbpZNrq, iQJlFKayEartcMPhJwDRROB
artcMPhJw

PGTKCQAwlMYlqNpdG, jxOZiMEDoTKCQAwlMYZcUdODZZf

TKCQAwlMY