using System;

public class Program

{

    public static void Main()

    {

    /*  Q1: For loop

​

Write a for-loop to calculate the product of all even numbers under 12 (including 12).

Hint: the counter doesn’t have to be 1.

    */

    int i;

    int product12 = 1;

    for (i = 2; i <= 12; i += 2)

        {

            product12 = i * product12;

        }

Console.WriteLine(product12);

​

    /*

Q2: While loop

Write a while loop to ask for three values from a user, and sum them up.

Hint: (1) use Console.ReadLine() to get data from a user, and convert it to an integer. (2) You can either use an array to sum them up after the loop or directly sum them up inside the loop.*/

​

    int counter = 0;

        int sum = 0;

        string input;

        int iInput;

    while(counter < 3)  

        {

        Console.WriteLine("Please Enter a Number.");

        input = Console.ReadLine();

​

​

​

        bool isValid = Int32.TryParse(input, out iInput);

​

            if (isValid == false)

                    {

​

                        Console.WriteLine("Please enter a valid number!");      

                        return;               

                    }

                    sum = iInput + sum;

        counter++;

        }

        Console.WriteLine(sum);

​

​

    }

}