Methods - Factorial division

using System;
class Program
{
    public static void Main()
    {
        double first = int.Parse(Console.ReadLine());
        double second = int.Parse(Console.ReadLine());

        double firstNumberFactorial = GetFactorial(first);
        double secondNumberFactorial = GetFactorial(second);

        double result = firstNumberFactorial / secondNumberFactorial;

        Console.WriteLine($"{result:f2}");
    }
    public static double GetFactorial(double number)
    {
        double factorial = number;

        for (double i = number - 1; i >= 1; i--)
        {
            factorial *= i;
        }

        return factorial;
    }
}