using System;

public class Program

{

    public static void Main()

    {

        int n = int.Parse(Console.ReadLine());

        int k= int.Parse(Console.ReadLine());

        int factorielN = 1;

        int factorielK= 1;

        for (int i = 1; i <= n; i++)

        {

            factorielN *=i;

        }

        for (int j = 1; j <= k; j++)

        {

            factorielK *=j;

        }

        Console.WriteLine(factorielN / factorielK);

    }

}