use strict;
use warnings;

my $n = <>;
my $count = 0;
my $ans;

for(my $i = 0; $i < $n; $i++) {
	$count += $i;
}
for(my $i = 1; $i < $n + 1; $i++) {
	if(($n % $i == 0)&&($count % $i == 0)) {
		$ans = $i;
	}
}

print "$ans\n";

exit;