instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
wLLwjL, arLwXm
answer:
Lw


question:
KTAFonizDqCVvucpJWrItdw, rfFonizDqCVvYbGhb
answer:
FonizDqCVv


question:
gzXanSoy, LsanSKDr
answer:

anS