use std::io::{Read, self};

fn main(){
    let mut lr = String::new();
    io::stdin().read_to_string(&mut lr).unwrap();

    
    let mut number = 1;
    for i in lr.chars(){
        if i == 'L'{
            number *= 2
        }else if i == 'R'{
            number = number * 2 + 1;
        }
    }
    println!("{}",number)
}