#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>
#include <string>

using namespace std;

int main() {
	string s;
	unsigned int road = 1;

	cin >> s;
	for (int i = 0; i < s.size(); i++) {
		road <<= 1;
		if (s[i] == 'R') {
			road |= 1;
		}
	}
	cout << road << endl;
	return 0;
}