C+N-1C+N-2C+N2-1C+N2-2C+N-3C+N2-3C+N-4C+N-5C+N2-4C+N4-1C+N4-2C+N-6C+N2-5C+N-7C+N4-3C+N-8C+N2-6C+N-9C+N-10C+N-11