using System;

public class Program

{

    public delegate int Calculator(int num1, int num2);

    public static void Main()

    {

        var CalcInstance = new Calc();

        Calculator calc = new Calculator(CalcInstance.Add);

        Console.WriteLine(calc(2, 10));

    }

}

​

​

​

public class Calc{

    public int Add(int num1, int num2)

    {

        return  num1 + num2;

    }

}