using System;
public class Program
{
    public static void Main()
    {
        //int num = int.Parse(Console.ReadLine() ?? string.Empty);
        //string[] pass = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        string load = Console.ReadLine() ?? string.Empty;

        if (load == "")
        {
            Console.WriteLine(1);
        }
        else
        {
            int count = 2;
            if (load[0] == 'R')
            {
                count++;
            }
            for (int i = 1; i < load.Length; i++)
            {
                count *= 2;//+= 3 * (i + 1);
                if (load[i] == 'R')
                {
                    count++;
                }

            }
            Console.WriteLine(count);
        }

    }
}