$tmp = @ARGV[0];
$i = 0;

while( 1 <= $tmp )
{
    $tmp /= 2;
    $i += 1;
}
print 2 ** $i;

##</code><code>##

sub nextpow2 {
    my $s= shift(@_);
    my $p= 1;
    $p *= 2   while  $p <= $s;
    return $p;
}