using System;

public class Calculator

{

    public static int Add(int num1, int num2)

   {

        return num1 + num2;

   }

    public static int sub(int num1, int num2)

   {

       return  num1 - num2;

   }

     public static int mul(int num1, int num2)

   {

        return  num1 * num2;

   }

     public static int div(int num1, int num2)

   {

       return num1 / num2;

   }

}

​

public class Program

{

    public string result;

   static void Main(string[] args)

  {

    int result1 = Calculator.Add(1,2);

    int  result2 = Calculator.sub(5,1);

    int result3 = Calculator.mul(4,3);

    int result4 = Calculator.div(8,2);

    Console.WriteLine("Addition :" + result1);

    Console.WriteLine("Subtraction :" + result2);

    Console.WriteLine("Multiplication :" + result3);

    Console.WriteLine("Division :" + result4);

  }

}