using System;

public class Program

{

    public static void Main()

    {

        // Ana Paola Mejia Rodriguez

        int pos;

        int num = 2;

​

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

        Console.WriteLine("What position of the previous series would you like to know?");

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

​

        for (int i = 2; i <= pos; i++)

        { 

            num = 2*num + 1;

        }

        Console.WriteLine(num);

​

​

    }

}