#/usr/bin/env perl

use strict;

my @sistemas = qw(Mac Windows);
my @windows = qw(XP Vista Seven);
my @Mac = qw(Leopard Lion Tiger);

my @OS = (\@sistemas,\@windows,\@Mac);

my $i = 0; my $n = 0;

while ($i < $#OS+1 ) {

foreach $n (0.. @{$OS[$i]}-1) {
print "Mi sistemas son $OS[$i][$n]\n";
}

$i+=1;

}