using System;
using System.Numerics;

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

            int fact1 = GetInput_Int();
            int fact2 = GetInput_Int();
            BigInteger fact11 = Factorial(fact1);
            BigInteger fact22 = Factorial(fact2);
            Console.WriteLine((fact11 / fact22).ToString("F2"));

        }
        static int GetInput_Int() { return int.Parse(Console.ReadLine()); }
        static double GetInput_Double() { return double.Parse(Console.ReadLine()); }
        static decimal GetInput_Decimal() { return decimal.Parse(Console.ReadLine()); }
        static float GetInput_Float() { return float.Parse(Console.ReadLine()); }
        static bool GetInput_Bool() { return bool.Parse(Console.ReadLine()); }
        static string GetInput() { return Console.ReadLine(); }


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