a-a a-c aaa aac aad aae aaf aao aap ac- aca acc acd ace acf aco acp ad- ada adc add ade adf ado adp aea aec aed aee aef aeo aep af- afa afc afd afe aff afo afp aoa aoc aod aoe aof aoo aop ap- apa apc apd ape apf apo app c-- caa cac cad cae caf cao cap cca ccc ccd cce ccf cco ccp cda cdc cdd cde cdf cdo cdp ce- cea cec ced cee cef ceo cep cfa cfc cfd cfe cff cfo cfp co- coa coc cod coe cof coo cop cpa cpc cpd cpe cpf cpo cpp daa dac dad dae daf dao dap dca dcc dcd dce dcf dco dcp dda ddc ddd dde ddf ddo ddp de- dea dec ded dee def deo dep dfa dfc dfd dfe dff dfo dfp doa doc dod doe dof doo dop dpa dpc dpd dpe dpf dpo dpp eaa eac ead eae eaf eao eap ec- eca ecc ecd ece ecf eco ed- eda edc edd ede edf edo edp eea eec eed eee eef eeo eep ef- efa efc efd efe eff efo efp eo- eoa eoc eod eoe eof eoo eop ep- epa epc epd epe epf epo epp faa fac fad fae faf fao fap fca fcc fcd fce fcf fco fcp fda fdc fdd fde fdf fdo fdp fea fec fed fee fef feo fep ffa ffc ffd ffe fff ffo ffp foa foc foe fof foo fop fpa fpc fpd fpe fpo fpp oaa oac oad oae oaf oao oap oc- oca occ ocd ocf oco ocp oda odc odd ode odf odo odp oea oec oed oee oef oeo oep of- ofa ofc ofd ofe off ofo ofp oo- ooa ooc ood oof ooo oop op- opa opc opd ope opf opo opp p-p paa pac pad pae paf pao pap pca pcc pcd pce pcf pco pcp pda pdc pdd pde pdf pdo pdp pea pec ped pee pef peo pep pfa pfc pfd pfe pff pfo pfp poa poc pod poe pof poo pop ppa ppc ppd ppe ppf ppo ppp