Module Module1

    Sub Main()

        Dim N As Integer = Console.ReadLine
        Dim bunsi As Integer

        If N Mod 2 = 0 Then
            bunsi = N \ 2
        Else
            bunsi = (N + 1) \ 2
        End If

        Console.WriteLine((bunsi / N).ToString("0.0000000000"))
        'Console.Read()

    End Sub

End Module
