instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
dxqZUOvRprXyFfjQfTWBhR, biSVjOvRprXyFfDtuFWQ
answer:
OvRprXyFf


question:
skZGHS, HsZGge
answer:
ZG


question:
bZuUEJ, mJuUkv
answer:

uU