#! /usr/bin/env perl
# $Id: hostnumber.pl 2666 2009-01-16 01:01:27Z jnieuwen $
# $URL: svn+ssh://shell.jeroen.se./usr/home/jnieuwen/subversion/files/trunk/h/hostnum/hostnumber.pl $
# $Author: jnieuwen $
# $Date: 2009-01-16 02:01:27 +0100 (Fri, 16 Jan 2009) $
# $Rev: 2666 $

use strict ;
use warnings ;

my $input = reverse $ARGV[0] ;
my $total = 0 ;
my $len = $ARGV[1] ;
my $number = $ARGV[0] ;
my $count = 2 ;

if (length($input) != $len) {
	print "$input does not have length $len\n" ;
	exit 1 ;
}

while ($input) {
	$total += $count++ * chop($input) ;
}

#print $total."\n" ;
#print $total % 11 ."\n" ;

my $checksum = 11 - ($total % 11) ;
$checksum = '0' if ($checksum == 11) ;
$checksum = 'X' if ($checksum == 10) ;

print "$checksum"."$number\n" ;