instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
ztkWLUJQXxP, fYluOkWLUJKDX
answer:
kWLUJ


question:
uGDJixAmSiVaFRmfKRM, NsTGxsJixAmSiVageSw
answer:
JixAmSiVa


question:
utzfIbAbCXzIWd, qKQvvnbAbCXzIvBnpeM
answer:

bAbCXzI