using System;
using System.Collections.Generic;

class Program
{
    static string InputPattern = "Input5";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("LR");
            //5
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("RLL");
            //12
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("RLLRLRLRRRLRL");
            //12986
        }
        else if (InputPattern == "Input4") {
            WillReturn.Add("");
            //1
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();
        int CurrRoad = 1;
        foreach (char EachChar in InputList[0]) {
            CurrRoad *= 2;
            if (EachChar == 'R') CurrRoad++;
        }
        Console.WriteLine(CurrRoad);
    }
}