using System;

public class Program

{

    public static void Main()

    {

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

        while ( i > 1)

        {

             if ( i % 2== 0)

             {

                 i= i/2;

             } 

            else 

            i = i*3 + 1;

         }

        Console.WriteLine(i);

    }

}