use strict;
use warnings;

my @x = (-60..-45);
my @y = (-57..-49);

my %union;
my %isect;

foreach my $e (@x, @y) { $union{$e}++ && $isect{$e}++ }

my @union = sort { $a <=> $b} keys %union;
my @isect = sort { $a <=> $b} keys %isect;

print "union: @union\n";
print "intersection: @isect\n";

__END__

union: -60 -59 -58 -57 -56 -55 -54 -53 -52 -51 -50 -49 -48 -47 -46 -45
intersection: -57 -56 -55 -54 -53 -52 -51 -50 -49