import java.util.*;

public class Run {
    public static void main (String arg[]) {
        Scanner scan = new Scanner(System.in);
        scan.useDelimiter("\\n");
        String S = scan.next();
        long Road = 1;
        for (int i = 0; i < S.length(); i++) {
            if (S.charAt(i)=='L') Road = Road*2;
            else Road = Road*2 + 1;
        }
        System.out.println(Road);
    }
}