a-a a-c aaa aac aae aao aap ac- aca acc ace aco acp aea aec aee aeo aep aoa aoc aoe aoo aop ap- apa apc ape apo app c-- caa cac cae cao cap cca ccc cce cco ccp ce- cea cec cee ceo cep co- coa coc coe coo cop cpa cpc cpe cpo cpp eaa eac eae eao eap ec- eca ecc ece eco eea eec eee eeo eep eo- eoa eoc eoe eoo eop ep- epa epc epe epo epp oaa oac oae oao oap oc- oca occ oco ocp oea oec oee oeo oep oo- ooa ooc ooo oop op- opa opc ope opo opp p-p paa pac pae pao pap pca pcc pce pco pcp pea pec pee peo pep poa poc poe poo pop ppa ppc ppe ppo ppp