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 n: usize = itr.next().unwrap().parse().unwrap();

    let mut x = 1;
    let mut ans = 0;
    while x * 2 <= n {
        ans += 1;
        x <<= 1;
    }
    if x != n {
        ans += x - (n + 1) / 2 + 1;
        ans += n & 1;
    }
    println!("{}", ans);
}