#include <iostream>
#include <list>
#include <vector>
#include <string>
#include <stdio.h>
#include <stdint.h>
using namespace std;

using uint = unsigned int;
using ll = long long;

#define CIN( LL , A ) LL A; cin >> A 
#define GETLINE( A ) string A; getline( cin , A ) 

int main()
{

  GETLINE( S );
  const uint& size = S.size();
  ll answer = 1;
  
  for( ll i = 0 ; i < size ; i++ ){

    // やったーp進数だー！
    answer = answer * 2 + ( S.substr( i , 1 ) == "L" ? 0 : 1 );
    
  }

  cout << answer << endl;
  return 0;

}