using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(CalcularFactorial(23));

        Console.WriteLine(CalcularFactorial(24));

​

    }

    static ulong CalcularFactorial(int n)

    {

        if (n == 0)            return 1;

        return (ulong)n * CalcularFactorial(n - 1);

    }

}