Factorial Division

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Functions
{
    class Program
    {
        static private double Factorial(double n)
        {
            if (n == 1 || n == 0)
            {
                return 1;
            }
            else
                return n * Factorial(n - 1);
        }
        private static void Main(string[] args)
        {
            double n = double.Parse(Console.ReadLine());
            double k = double.Parse(Console.ReadLine());
            double result = Factorial(n) / Factorial(k);
            Console.WriteLine($"{result:F2}");
        }

    }
}