Let S be the set of (α,β),π<α,β<2π,for which the complex number
\(\frac{1-i\sinα}{1+2i\sinα}\) is purely imaginary and \(\frac{1+i\cosβ}{1-2i\cosβ}\) is purely real,
Let \(Zαβ = \sin2α+i\cos2β, (α,β) ∈ S\). Then
\(\sum_{(\alpha, \beta) \in S} \left(iZ_{\alpha\beta} + \frac{1}{iZ_{\alpha\beta}}\right)\)
is equal to