Guess the missing item from this list: α-7, β-6, β-1, α-4, β-5, β-4, α-6, α-3, α-0, β-3, α-2, β-2, α-5, α-1, α-8, β-0.
Directly answer with only one item. Item format should match the list format. Provide no explanation. Answer format: "{item}."