#! perl -slw
use strict;
my $result = "\0" x 100;
while (my ($start, $end) = split ' ', <DATA>) {
	substr($result, $start, $end - $start + 1) = 1 x ($end - $start + 1);
}
my (@results, $start);
for (0 .. length $result) {
	my $c = substr($result, $_, 1);
	next if not $start and $c ne '1';
	$start = $_ if $c eq '1' and not $start;
	next if $start and $c eq '1';
	push @results, [$start, $_-1];
	$start = undef;
}
print map{local $"='-'; "[@$_] "}@results; #!"

__END__
17 19
34 39
26 29
53 57
43 47
58 59
40 45
30 33
20 24
10 15
6 9
1 4
35 45
7 15