sub keycmp {
    
    $a =~ /^(\D*)(\d*)$/;
    my $a_txt = $1;
    my $a_num = $2;

    $b =~ /^(\D*)(\d*)$/;
    my $b_txt = $1;
    my $b_num = $2;
    
    if ($a_txt eq $b_txt) {
        return $a_num <=> $b_num
    }
    else {
        return $a_txt cmp $b_txt
    }

}

@result = sort keycmp keys %{$hash->{"AAA"}};
print "@result\n";