#!/usr/bin/perl -w

# the first argument is the maximum extent in map units
# divide by a resonable number of annotations per edge
$x = $ARGV[0] / 10;

print round_up($x) , "\n";

# round to a resonable scale
# found at:
# http://www.perlmonks.org/?node_id=599865

sub round_up {
  my $n = shift;
  my $scale = 10**int(log($n)/log(10));
  $n = 9 if $scale == 1; #magic for single digits
  if ($n > $scale) {
    $n = int($n/$scale+1)*$scale;
  }
  $n;
}