using System;
using System.Linq;
namespace Task29718822
{
internal class Program
{
private static void Main(string[] args)
{
Console.WriteLine("Enter n and m:");
int n = int.Parse(Console.ReadLine()), m = int.Parse(Console.ReadLine());
Console.WriteLine(Enumerable.Range(n - (m - 1), m).Aggregate(1, (x, y) => x * y));
}
}
}