use strict;
use warnings;

use Test::More tests => 1;

my @in   = qw/a-3 a-1 a-2/;
my @want = qw/a-1 a-2 a-3/;

my @have = sort { substr ($a, 2) <=> substr ($b, 2) } @in;
is_deeply \@have, \@want;