$string = "AFP254";
$number = 1;
foreach('A'..'Z'){
        $alpha_nums{$_} = $number;
        $number++;
}
                                                                            
@string = split("", $string);

$total = 0;
foreach(@string){
        if(/\S/ && !/\d/){
                $_ = $alpha_nums{$_};
        }
        $total = $_+$total;
}
print "$total\n";