}
if (extra_pages)
{
ret.force_.insert (ret.force_.end (), extra_pages, BAD_SPACING_PENALTY);
ret.systems_per_page_.insert (ret.systems_per_page_.end (), extra_pages, 0);
}
if (extra_pages)
{
ret.force_.insert (ret.force_.end (), extra_pages, BAD_SPACING_PENALTY);
ret.systems_per_page_.insert (ret.systems_per_page_.end (), extra_pages, 0);