instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
PShMbsbexXGlpBuMMDZZS, sVqGxSexXGlpBxuHXoI
answer:
exXGlpB


question:
PQCjJwXurLeN, vsjJwXuOy
answer:
jJwXu


question:
ziJtPJJDoOTyZUtqxR, xGdDoOTyZUrvuvgS
answer:

DoOTyZU