using System;

public class Program

{

    public static void Main()

    {

        // We need this long integer to be able to store our answers:

        long iAnswer=0;

        // Create the function 'factorial' returning a lonng int and passing int an int as a parameter:

        static long factorial(int i)

        {

            if(i<=1)

                return 1;       // This interrupts the function and causes a base return.

            // If the parameter passed in is not small enough, call the funtion again with i-1 parameter:

            return i * factorial(i-1);

        }

        // Do the following 20 times - find the factorials of 1 up to 20:

        for(int j=1; j<21; j++)

        {

            iAnswer = factorial(j);

            Console.WriteLine(iAnswer);

        }

    }

}