instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
ftvxfhsnJEygzV, JYxSfhsnJnIqkW
answer:
fhsnJ


question:
AxRSlkQfWHrdlgQG, iXIOrmlkQfWHTy
answer:
lkQfWH


question:
cnBgJGRZEnaq, UaJGRZEJWTno
answer:

JGRZE