a-a a-c aaa aac aan aao aap ac- aca acc acn aco acp an- ana anc ann ano anp aoa aoc aon aoo aop ap- apa apc apn apo app c-- caa cac can cao cap cca ccc ccn cco ccp cn- cna cnc cnn cno cnp co- coa coc con coo cop cpa cpc cpn cpo cpp naa nac nan nao nap nca ncc ncn nco ncp nna nnc nnn nno nnp no- noa noc non noo nop npa npc npn npo npp oaa oac oan oao oap oc- oca occ ocn oco ocp on- ona onc onn ono onp oo- ooa ooc oon ooo oop op- opa opc opn opo opp p-p paa pac pan pao pap pca pcc pcn pco pcp pn- pna pnc pnn pno pnp poa poc pon poo pop ppa ppc ppn ppo ppp