using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;

class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        string inpt = Reader.ReadLine();
        if (inpt == null)
        {
            inpt = string.Empty;
        }

        TreeNode current = new TreeNode(1);
        List<TreeNode> list = new List<TreeNode>();
        list.Add(current);
        int idx = 1;
        for (int i = 0; i < inpt.Length; i++)
        {
            List<TreeNode> subList = new List<TreeNode>();
            for (int j = 0; j < list.Count; j++)
            {
                list[j].AddItems(++idx, ++idx);
                subList.Add(list[j].NodeLeft);
                subList.Add(list[j].NodeRight);
            }
            list = subList;
            if (inpt[i] == 'R')
            {
                current = current.NodeRight;
            }
            else
            {
                current = current.NodeLeft;
            }
            
        }

        Console.WriteLine(current.ID);

    }

    public class TreeNode
    {
        public int ID;
        public TreeNode(int id)
        {
            this.ID = id;
        }
        public TreeNode NodeLeft;
        public TreeNode NodeRight;

        public void AddItems(int leftId, int rightId) {
            this.NodeLeft = new TreeNode(leftId);
            this.NodeRight = new TreeNode(rightId);
        }

    }

    public class Reader
    {
        public static bool IsDebug = true;
        private static String PlainInput = @"








 
";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        public static int[] GetInt(char delimiter = ' ', bool trim = false)
        {
            string inptStr = ReadLine();
            if (trim)
            {
                inptStr = inptStr.Trim();
            }
            string[] inpt = inptStr.Split(delimiter);
            int[] ret = new int[inpt.Length];
            for (int i = 0; i < inpt.Length; i++)
            {
                ret[i] = int.Parse(inpt[i]);
            }
            return ret;
        }
    }
    static void Main()
    {
        Program prg = new Program();
        prg.Proc();
    }
}