use strict;
use warnings;

my @nums = get_numbers_from_ranges ('2,10-13,2-5');

print "@nums";

sub get_numbers_from_ranges {
    my @ranges = split ',', shift;
    my @numbers;
    my %seen;

    for my $range (@ranges) {
        my ($start, $end) = sort {$a <=> $b} split '-', $range;
        
        $end ||= $start;
        ! $seen{$_}++ and push @numbers, $_ for $start .. $end;
    }

    return @numbers;
}

##</code><code>##

2 10 11 12 13 3 4 5