instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
NwmTIZSnlKGG, qAYIZSnfWRd
answer:
IZSn


question:
CiElmOvTqJGVJkfSaDRzE, EjDJwMyxTvTqJGVJkfluB
answer:
vTqJGVJkf


question:
bBGhTwDrRSXjds, ommTwDrRsQL
answer:

TwDrR