instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
rlBoVyFsYqpmmQmelGBg, iKKaIyFsYqpmmWcrKn
answer:
yFsYqpmm


question:
bVlwKYBYmcNq, hBlwKYBprL
answer:
lwKYB


question:
uxqzNjRVfdA, hIqzNjRvcQI
answer:

qzNjR