using System;

namespace strong_number
{
    class Program
    {
        static void Main()
        {

            int fact1 = GetInput_Int();
            int fact2 = GetInput_Int();
            fact1 = Factorial(fact1);
            fact2 = Factorial(fact2);


            Console.WriteLine((fact1 / fact2).ToString("F2"));

        }
        static int GetInput_Int() { return int.Parse(Console.ReadLine()); }



        static int Factorial(int number) { int fact = 1; for (int loop = 1; loop <= number; loop++) { fact = fact * loop; } return fact; }
    }
}