use strict;
use warnings;

sub elide {
	my ($start,$end) = @_;
	if ((my $diff1 = length($end) - length($start)) > 0) {
		return "$start-$end";
	} elsif ($diff1 == 0) {
		if ($start == $end) {
			return $start;
		} else {
			if ((my $diff2 = length($end) - length($end - $start)) > 0) {
				$end %= 10 ** (length($end) - $diff2);
			} 
			return "$start-$end";
		}
	}
}

while ( <DATA> ) {
  print elide( split ' ', $_ ), "\n";
}

__DATA__
1   32
4   19
28  39
34  123
321 321
324 329
325 349
340 509
999 1000
1000 1001