#! /usr/bin/perl -w

open ( IN, "$ARGV[0]" );
$first = $ARGV[1];
$last = $first;
$list = $first;
$new = $first;

while ( <IN> ) {
  chomp;
  if ($_ == $first) {
    $last = $_;
    next;
  }
  if ( $_ == $last + 1 ) { 
    $new = $list."-".$_;
    $last = $_;
  } else {
    $list = $new.",".$_;
    $new = $list;
    $last = $_;
  }
}
print "          $list\n";