using System;

public class Program

{

    public static void Main()

    {

        //While 10

        double i1 = 1;

        double sum1 = 1;

        while(i1 <= 10)

        {

            sum1 = sum1 * i1;

            i1++;

        }

        Console.WriteLine("While: The product of the first 10 number is " + sum1);

        //While 20

        double i2 = 1;

        double sum2 = 1;

        while(i2 <= 20)

        {

            sum2 = sum2 * i2;

            i2++;

        }

        Console.WriteLine("While: The product of the first 20 number is " + sum2);

        //Do While 10

        double i3 = 1;

        double sum3 = 1;

        do

        {

            sum3 = sum3 * i3;

            i3++;

        } while(i3 <= 10);

        Console.WriteLine("Do While: The product of the first 10 number is "+ sum3);

        //Do While 20

        double i4 = 1;

        double sum4 = 1;

        do

        {

            sum4 = sum4 * i4;

            i4++;

        } while(i4 <= 20);

        Console.WriteLine("Do While: The product of the first 10 number is "+ sum4);

        //For Loops 10

        double i5 = 1;

        double sum5 = 1;

        for(i5 = 1;i5 <= 10;i5++)

        {

            sum5 = sum5 * i5;

        }

        Console.WriteLine("For Loops: The product of the first 10 number is "+ sum5);

        //For Loops 20

        double i6 = 1;

        double sum6 = 1;

        for(i6 = 1;i6 <= 20;i6++)

        {

            sum6 = sum6 * i6;

        }

        Console.WriteLine("For Loops: The product of the first 10 number is "+ sum6);

    }

}