instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
uRLpAWCotLmxcSmKyvo, laotLmxcSmKyBwVfJB
answer:
otLmxcSmKy


question:
yiKkIxbKvNk, znaIxbKggg
answer:
IxbK


question:
ifJUsOCyjLVZYmnZCzzHj, ayyWwGUsOCyjLVZRhdsmM
answer:

UsOCyjLVZ