sub nearest {
   my ($num) = @_;
   $num += 0;

   return 0 unless $num;

   my $f = $num <=> 0;
   $num = abs($num);

   while ($num >= 10) { $num /= 10; $f *= 10; }
   while ($num <   1) { $num *= 10; $f /= 10; }

   return int($num + 0.5) * $f;
}