a-a a-c aaa aac aaf aao aap aar ac- aca acc acf aco acp acr af- afa afc aff afo afp afr aoa aoc aof aoo aop aor ap- apa apc apf apo app apr ar- ara arc arf aro arp arr c-- caa cac caf cao cap car cca ccc ccf cco ccp ccr cfa cfc cff cfo cfp cfr co- coa coc cof coo cop cor cpa cpc cpf cpo cpp cpr cra crc crf cro crp crr faa fac faf fao fap far fca fcc fcf fco fcp fcr ffa ffc fff ffo ffp ffr foa foc fof foo fop for fpa fpc fpo fpp fpr fra frc frf fro frp frr oaa oac oaf oao oap oar oc- oca occ ocf oco ocp ocr of- ofa ofc off ofo ofp ofr oo- ooa ooc oof ooo oop oor op- opa opc opf opo opp opr or- ora orc orf oro orp orr p-p paa pac paf pao pap par pca pcc pcf pco pcp pcr pfa pfc pff pfo pfp pfr poa poc pof poo pop por ppa ppc ppf ppo ppp ppr pra prc prf pro prp prr ra- raa rac raf rao rap rar rca rcc rcf rco rcp rcr rfa rfc rff rfo rfp rfr roa roc rof roo rop ror rpa rpc rpf rpo rpp rpr rra rrc rrf rrp rrr