using System;

public class Program

{

    private static void Plus( double firstNum ,double secondNum)

    {

        Console.WriteLine(firstNum+secondNum);

    }

    private static void Minus(double firstNum ,double secondNum)

    {

        Console.WriteLine(firstNum – secondNum);

    }

    private static void Deleno(double firstNum ,double secondNum)

    {

        Console.WriteLine(firstNum/secondNum);

        private static void Umnogeno(double firstNum ,secondNum)

        {

            Console.WriteLine(firstNum * secondNum);

        }

        string command = Console.ReadLine();

        double a = double.Parse(Console.ReadLine());

        double b = double.Parse(Console.ReadLine());

            switch (command)

        {

                case "Add": Plus (a,b);

                break:

                case " substract": Minus (a,b);

                break:

                case " multiply": Umnogeno (a,b);

                break:

                case "divide": Deleno (a,b);

                    break:

    }   }           

}