using System;  

delegate int Calculator(int n);//declaring delegate  

public class DelegateExample  

{  

    static int number = 100;  

    public static int add(int n)  

    {  

        number = number + n;  

        return number;  

    }  

    public static int mul(int n)  

    {  

        number = number * n;  

        return number;  

    }  

    public static int getNumber()  

    {  

        return number;  

    }  

    public static void Main(string[] args)  

    {  

        Calculator c1 = new Calculator(add);//instantiating delegate  

        Calculator c2 = new Calculator(mul);  

        c1(20);//calling method using delegate 

        c2(0);

        Console.WriteLine("After c1 delegate, Number is: " + getNumber());  

        Console.WriteLine("After c2 delegate, Number is: " + getNumber());  

    }  

}