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: u64 = itr.next().unwrap().parse().unwrap();
    let mut a = Vec::new();
    for i in 0..60 {
        if n >> i & 1 == 1 {
            a.push(i);
        }
    }
    let target = 1u64 << a.len() - 1;
    let mut ans = 0;
    for i in 0..60 {
        if target >> i & 1 == 1 {
            ans += 1 << a[i];
        }
    }
    println!("{}", ans);
}