using System;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine(Add(1, 2, 3, 4, 5));      

    }

    public static int Add(params int[] numbers) 

    {

        int sum = 0;

        foreach (int n in numbers)

        {

            sum += n;

        }

        return sum;

    }

}

​