N+C-1N+C-2N+C-3N+C-4N+C-5N+C-6N+C-7N+C-8N+C-9N+C-10N+C-11N+C-12N+C-13N+C-14N+C-15N+C-16N+C-17N+C-18N+C-19N+C-20