using System;

public class Program

{

    public static void Main()

    {

        long sum10 = 1;

        int number10 = 1;                                           

        do 

        {                                                                 

            sum10 *= number10;

            number10++;                                               

        } while (number10 < 11);

        Console.WriteLine("the product of the first 10 numbers is: " + sum10);

        long sum20 = 1;

        int number20 = 1;                                           

        do 

        {                                                                 

            sum20 *= number20;

            number20++;                                               

        } while (number20 < 21);

        Console.WriteLine("the product of the first 10 numbers is: " + sum20);

    }

}