#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <iomanip>
#include <cmath>
#include <functional>
using namespace std;
#define diff(x,y) ((x > y) ? (x - y) : (y - x))
#define us(x) (x > 0) ? x : x * -1

long long int twoten(vector <bool> num);

int main() {
	int ans = 1;
	string str;
	cin >> str;
	vector <bool> num(1,1);
	for (int i = 0; i < str.size(); i++) {
		if (str[i] == 'L') {
			num.push_back(0);
		}
		else {
			num.push_back(1);
		}
	}
	cout << twoten(num) << endl;
	return 0;
}

long long int twoten(vector <bool> num) {
	long long int ret = 0;
	for (int i = num.size() - 1; i >= 0; i--) {
		ret += num[num.size() - i - 1] * pow(2, i);
	}
	return ret;
}