Guess the missing item from this list: α-9, β-3, α-0, α-4, β-1, α-8, α-6, α-7, β-4, β-6, α-2, β-2, β-5, α-5, α-3, β-0.
Directly answer with only one item. Item format should match the list format. Provide no explanation. Answer format: "{item}."