#![allow(non_snake_case)]
#![allow(unused_imports)]
//use itertools::Itertools;
//use proconio::input;
//use proconio::marker::*;
use std::cmp::Reverse;
use std::collections::*;

fn main() {
    input! {
        n:usize,
    }
    const D: usize = 60;

    let mut pow2 = 1usize;
    for i in 0..D {
        if n & (1 << i) != 0 {
            pow2 *= 2;
        }
    }

    let m = pow2 / 2;
    let mut cnt = 0usize;
    let mut ans = 0usize;
    for i in 0..D {
        if n & (1 << i) != 0 {
            if m & (1 << cnt) != 0 {
                ans |= 1 << i;
            }

            cnt += 1;
        }
    }

    println!("{}", ans);
}
mod input {
    #[macro_export]
    macro_rules! input {
        (source = $s:expr, $($r:tt)*) => {
            let mut iter = $s.split_whitespace();
            input_inner!{iter, $($r)*}
        };
        ($($r:tt)*) => {
            let s = {
                use std::io::Read;
                let mut s = String::new();
                std::io::stdin().read_to_string(&mut s).unwrap();
                s
            };
            let mut iter = s.split_whitespace();
            input_inner!{iter, $($r)*}
        };
    }

    #[macro_export]
    macro_rules! input_inner {
        ($iter:expr) => {};
        ($iter:expr, ) => {};

        ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
            let $var = read_value!($iter, $t);
            input_inner!{$iter $($r)*}
        };
    }

    #[macro_export]
    macro_rules! read_value {
        ($iter:expr, ( $($t:tt),* )) => {
            ( $(read_value!($iter, $t)),* )
        };

        ($iter:expr, [ $t:tt ; $len:expr ]) => {
            (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
        };

        ($iter:expr, chars) => {
            read_value!($iter, String).chars().collect::<Vec<char>>()
        };

        ($iter:expr, usize1) => {
            read_value!($iter, usize) - 1
        };

        ($iter:expr, $t:ty) => {
            $iter.next().unwrap().parse::<$t>().expect("Parse error")
        };
    }
}