fn main() {
    let stdin = std::io::stdin();
    let mut rd = ProconReader::new(stdin.lock());

    let d: i64 = rd.get();
    for y in ((d / 2 - 100000)..=(d / 2 + 100000)).filter(|&y| 1 <= y && y <= d) {
        if (0..60)
            .scan((0, y), |(s, x), _| {
                *s += *x;
                *x /= 2;
                Some((*s, *x))
            })
            .any(|(s, _)| s == d)
        {
            println!("{}", y);
            return;
        }
    }
    println!("{}", d);
}

pub struct ProconReader<R: std::io::Read> {
    reader: R,
}

impl<R: std::io::Read> ProconReader<R> {
    pub fn new(reader: R) -> Self {
        Self { reader }
    }
    pub fn get<T: std::str::FromStr>(&mut self) -> T {
        use std::io::Read;
        let buf = self
            .reader
            .by_ref()
            .bytes()
            .map(|b| b.unwrap())
            .skip_while(|&byte| byte == b' ' || byte == b'\n' || byte == b'\r')
            .take_while(|&byte| byte != b' ' && byte != b'\n' && byte != b'\r')
            .collect::<Vec<_>>();
        std::str::from_utf8(&buf)
            .unwrap()
            .parse()
            .ok()
            .expect("Parse Error.")
    }
}