using System;

public class Program

{

    public static void Main()

    {

        //Regina Muñoz 2B

        int n, x= 2, y =3; 

        Console.WriteLine("2, 5, 11, 23, 47...");

        Console.WriteLine();

        Console.WriteLine("From the previous series, what position would you like to know");

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

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

            if(i >1) {

             x= x + y;

             y= y * 2;

            }

        }

            Console.WriteLine("");

            Console.WriteLine(x);

    }

}