context: The Uranus ring system includes 13 of clearly distinguishable rings. By distance from the planet, they are arranged in the following order: 1986U2R / ζ, 6, 5, 4, α, β, η, γ, δ, λ, ε, ν, μ [8]. They can be divided into 3 groups: 9 narrow main rings (6, 5, 4, α, β, η, γ, δ, ε) [9], two dust rings (1986U2R / ζ, λ) [10] and two outer the rings (μ, ν) [8] [11].
question: How many rings does Uranus have ??
answers.text: 13