a-a a-c aaa aac aae aaf aao aap ac- aca acc ace acf aco acp aea aec aee aef aeo aep af- afa afc afe aff afo afp aoa aoc aoe aof aoo aop ap- apa apc ape apf apo app c-- caa cac cae caf cao cap cca ccc cce ccf cco ccp ce- cea cec cee cef ceo cep cfa cfc cfe cff cfo cfp co- coa coc coe cof coo cop cpa cpc cpe cpf cpo cpp eaa eac eae eaf eao eap ec- eca ecc ece ecf eco eea eec eee eef eeo eep ef- efa efc efe eff efo efp eo- eoa eoc eoe eof eoo eop ep- epa epc epe epf epo epp faa fac fae faf fao fap fca fcc fce fcf fco fcp fea fec fee fef feo fep ffa ffc ffe fff ffo ffp foa foc foe fof foo fop fpa fpc fpe fpo fpp oaa oac oae oaf oao oap oc- oca occ ocf oco ocp oea oec oee oef oeo oep of- ofa ofc ofe off ofo ofp oo- ooa ooc oof ooo oop op- opa opc ope opf opo opp p-p paa pac pae paf pao pap pca pcc pce pcf pco pcp pea pec pee pef peo pep pfa pfc pfe pff pfo pfp poa poc poe pof poo pop ppa ppc ppe ppf ppo ppp