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