$ perl -Mstrict -Mwarnings -E'
> my @notSorted = qw{ Beep Ape Circus Arg };
> my( @A, @trash );
> push @{ $_ =~ m{^A} ? \ @A : \ @trash }, $_ for sort @notSorted;
> do {
>    local $" = q{, };
>    say qq{@A};
>    say qq{@trash};
>    };'
Ape, Arg
Beep, Circus
$