08. Factorial Division

using System;

namespace FactorialDivision
{
    class Program
    {
        static void Main(string[] args)
        {
            int a = int.Parse(Console.ReadLine());
            int b = int.Parse(Console.ReadLine());

            Console.WriteLine($"{(Factorial(a) / Factorial(b)):f2}");
        }

        static double Factorial(int n)
        {
            if (n == 0)
            {
                return 1;
            }

            return n * Factorial(n - 1);
        }
    }
}