instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
bUcuzFgsdfojVR, IdcuzFgsdMRgtMA
answer:
cuzFgsd


question:
BmxgSFWBlVX, kGgKrgSFWBlGunFcZ
answer:
gSFWBl


question:
AXvXJsQ, OMvXJtAh
answer:

vXJ