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