import java.util.*;
public class Test11 {
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    String[] line;
    line=sc.nextLine().split(" ");
    int n=line[0].length();
    int route=1;
    for(int i=0;i<n;i++){
      route*=2;
      if(line[0].charAt(i)=='R'){
        route++;
      }
    }
    System.out.println(route);
    sc.close();
  }
}