instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
ssKUiWgGqsXYlFOOc, JDcVTmCgGqsXYlxYE
answer:
gGqsXYl


question:
mmDhYqPJC, qThYqxW
answer:
hYq


question:
NUBqkYNJlVP, CzgkYNJIQlM
answer:

kYNJ