#include <iostream>

int main() {
    std::string S;
    std::cin >> S;
    int now = 1;
    for (size_t i = 0; i < S.size(); i++) {
        switch (S[i]) {
            case 'L':
                now = 2 * now;
                break;
            case 'R':
                now = 2 * now + 1;
                break;
            default:
                return 1;
        }
    }
    std::cout << now << std::endl;
}