using System;

public class Program

{

 static private double add(double a, double b, double c)

{

​

  return a+b+c;

​

​

​

}

static void Main(string[] args)

{double x = 57;

double y = -36.5639;

double z = -27.3;

Console.WriteLine(add(x,y,z));

Console.ReadLine();

}

​

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Console.WriteLine("Please enter 3 numbers"); 

​

    }

}