using System;

public class Program

{

    public static void Main()

    {

        //1

        double sumWhile = 1;

        int numberWhile = 1;

​

        //While 20

        while (numberWhile < 21)

        {

            sumWhile = sumWhile * numberWhile;

            numberWhile++;

        }

​

        Console.WriteLine("While Loop 20: " + sumWhile);

​

        double sumDo = 1;

        int numberDo = 1;

​

        //Do While 20

        do

        {

            sumDo = sumDo * numberDo;

            numberDo++;

​

        } while (numberDo < 21);

​

        Console.WriteLine("Do While Loop 20: " +  sumDo);

        //For 20

        double sumFor = 1;

        int numberFor;

        for(numberFor = 1; numberFor < 21; numberFor++){

            sumFor = sumFor * numberFor;

        }

        Console.WriteLine("For Loop 20: " + sumFor);

        double sumWhile10 = 1;

        int numberWhile10 = 1;

​

        //While 10

        while (numberWhile10 < 11)

        {

            sumWhile10 = sumWhile10 * numberWhile10;

            numberWhile10++;

        }

​

        Console.WriteLine("While Loop 10: " + sumWhile10);

​

        double sumDo10 = 1;

        int numberDo10 = 1;

​

        //Do While 10

        do

        {

            sumDo10 = sumDo10 * numberDo10;

            numberDo10++;

​

        } while (numberDo10 < 11);

​

        Console.WriteLine("Do While Loop 10: " +  sumDo10);

        //For 10

        double sumFor10 = 1;

        int numberFor10;

        for(numberFor10 = 1; numberFor10 < 11; numberFor10++){

            sumFor10 = sumFor10 * numberFor10;

        }

        Console.WriteLine("For Loop 10: " + sumFor10);

        //2

        /*

            Break will stop the loop basked on a condition

            Continue will continue to the next loop iterataion based on a condition

        */

        //3

        string stop = "Y";

        int number = 0;

        while (number < 11) {

            if(stop == "Y"){

            Console.WriteLine(number);

            number++;

            Console.WriteLine("Y or N to continue? ");

            stop = Console.ReadLine();

            continue;

            } else {

                break;  

            }

        }

    }

}