instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
BVipiZoGXaWdjmDsxWP, yxppsiYkiZoGXaWdjoDRuKW
answer:
iZoGXaWdj


question:
NUuLSmDjCKcJPc, lGGSLIDjCKcJBo
answer:
DjCKcJ


question:
lnwOOuQcto, oQSrwOOuSs
answer:

wOOu