using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var num = 6.7812367890494334556m;

        //var num = 6.00m;

        Console.WriteLine(NullSafeToString(num));

    }

    public static string NullSafeToString(decimal obj)

    {

            return obj != 0.0m ? obj.ToString("0.00########") : "0.0";

    }

}