fn main() {
    let mut input = String::new();
    let _ = std::io::stdin().read_line(&mut input);

    let mut number = 1;
    for c in input.trim().chars() {
        number = match c {
            'L' => number * 2,
            _ => number * 2 + 1,
        };
    }

    println!("{}", number);
}