instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
ocjsZZfSBBopDtgWUT, rWmgzsZZfSBBoGWQ
answer:
sZZfSBBo


question:
XwBMFIV, SNLBMFZQ
answer:
BMF


question:
rEchuTNyG, KJZychuTmGh
answer:

chuT