import java.util.Scanner;

public class ThirdClass {
    public static void main(String[] args) {


        Scanner input = new Scanner(System.in);

        int factorialNum = Integer.parseInt(input.nextLine());
        int divideNum = Integer.parseInt(input.nextLine());

        calculations(factorialNum,divideNum);

        }

        static void calculations (int a,int b){
            int facNum = 1;                    //i*i-1 //20 * 3
            for (int i = a; i >= 1; i--) { //5*4*3*2*1;
               facNum = facNum*i;
            }

            double divNum = (double)(facNum/b);
            System.out.printf("%.2f",divNum);
        }


    }