#include <iostream>
using namespace std;
int main() {
    string s;
    cin >> s;
    int road_num = 1;
    for(int i=0;i<s.size();i++) {
        if(s[i]=='L')
            road_num = 2*road_num;
        else
            road_num = 2*road_num+1;
    }
    cout << road_num << endl;
}