instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
NxgzLSzFGa, JvLzLSzsuj
answer:
zLSz


question:
nOfXJySmVaJIindcJavXh, YpJWmVaJIindcJnoxyRvunG
answer:
mVaJIindcJ


question:
yqsQdL, nbsQEH
answer:

sQ