#!/usr/bin/env perl

use strict;
use warnings;
use feature 'say';
use experimental 'signatures';

sub main ($n) {
    # Find the first power of two greater than n
    my $p = 1;
    $p *= 2 while ( $p <= $n );

    # Print the inverse of n
    say $p- $n - 1;
}

main( $ARGV[0] );