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