using System;

public class Program

{

    public static void Main()

    {

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

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

        for ( int i = n-1; i>0; i--)

        {n=n*i;}

        for ( int i = k-1; i>0; i--)

        {k=k*i;}

        Console.WriteLine(n/k);

    }

}