using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Problem_F
{
    class Program
    {
        public static void Monom (double a, int n, ref double polynomial)
        {
            int i = 1;
                double monomial=a;
            polynomial = 1;
           while (i<n+1)
            {
                polynomial += monomial;
                monomial = monomial * a;
                i++;
            }
        }
        static void Main(string[] args)
        {
            double a, polynomial=1;
            int n;
            if (!double.TryParse(Console.ReadLine(), out a) || (!int.TryParse(Console.ReadLine(), out n))||(n<1))
                Console.WriteLine("wrong");
            else
            {
                Monom(a, n, ref polynomial);
                Console.WriteLine(Math.Round(polynomial, 5));
            }
        }
    }
}