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:
UTdardKNThdYrGKMqZPeg, mvrThdYrGKMlcCxBtak
answer:
ThdYrGKM


question:
pIpJhJyhyEfKHnzBLebQ, ogjwCLasoXhJyhyEfKHnaJffNE
answer:

hJyhyEfKHn