using System;

public class Program

{

    public static void Main()

    {

        //Pedro Sánchez

        //With this practice we will learn how to use double and int data and how to do the four basic mathematical operations

        int a, b; //Declare two variables where we can save integer numbers

        double c, d; //Declare two variables where we can save numbers with decimals

        //Declare double variables for the basic operations in case the result has decimals

        double sum, subtraction, product, division;

        //Now let's assign some values to our variables

        a = 3;

        b = 9;

        c = 5.5;

        d = 2.7;

        sum = a + b;

        Console.WriteLine("The sum of " + a + " and " + b + " is: " +sum);

        Console.WriteLine(); //Skip a line with an empty WriteLine

        subtraction = d - b;

        Console.WriteLine(d  + " minus " + b + " is: " +subtraction);

        Console.WriteLine();

        product = b * c;

        Console.WriteLine("The product of " + b + " and " + c + " is: " +product);

        Console.WriteLine();

        division = d / b;

        Console.WriteLine("The division of " + d + " by " + b + " is: " +division);

        Console.WriteLine();

        sum = c + d;

        Console.WriteLine("The sum of " + c + " and " + d + " is: " +sum);

        Console.WriteLine();

        //Now the same but asking the user

        Console.WriteLine("Hey! Write a number");

        a = int.Parse(Console.ReadLine()); //int.Parse or double.Parse is needed to save the answer of the user as a number

        Console.WriteLine("Write another number, please");

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

        sum = a + d; //Aquí estoy sumando los números del usuario

        Console.WriteLine("The sum of " + a + " and " + d + " is: " +sum);

    }

}