using System;

public class Program

{

    public static void Main()

    { 

        double x = double.Parse(Console.ReadLine());

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

        int f = 1;

        double r;

        double sum = 1;

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

        {

            f = f * i;

            r = Math.Pow(x, i);

            sum = sum + (r / f);

        }

        Console.WriteLine(sum);

    }

}