using System;

​

public class Program

{

    public static void Main()

    {

        int post;

        int num1 = 3;

        Console.WriteLine("3, 11, 35, 107, 323");

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

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

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

        {

            num1= 3*num1+2;

        }

​

        Console.WriteLine(num1);

        Console.WriteLine("Thank You , have a great day , see you soon! 7u7");

    }

}