using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var result = 0.0;

        if (double.TryParse(("20..3").Replace("..","."), out result)) 

            Console.WriteLine(result);

        else

            Console.WriteLine("TryParse failed to convert 20..3 to double");

    }

}