using System;

public class Program

{

    public static void Main()

    {

        var value = Double.NegativeInfinity;

        var str = value.ToString();

        Console.WriteLine(str);

        Console.WriteLine(Double.Parse(str));

​

        value = Double.NaN;

        str = value.ToString();

        Console.WriteLine(str);

        Console.WriteLine(Double.Parse(str));

    }

}