#!perl
use strict;
use warnings;

my @preferred = qw(best good normal bad worst);
my @routers = qw (asda adsas asdasds);

foreach my $router(@routers){
        my $best_of = best_of($router);
}


sub best_of {
    my $router = shift;
    my %available;
    @available{get_available($router)};# get_available return a list
                                       # used as keys of %available hash
                                       # for our comfort
    map { return $_ if exists %avalable{$_} } @preferred;

}