use std::io::*;

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();

    let mut itr = s.trim().split_whitespace();
    let s: Vec<char> = itr.next().unwrap_or_default().chars().collect();

    let mut ans = 1;
    for c in s {
        if c == 'L' {
            ans = ans * 2;
        } else {
            ans = ans * 2 + 1;
        }
    }
    println!("{}", ans);
}