a-a a-c aaa aac aaf aao aar aas ac- aca acc acf aco acr acs af- afa afc aff afo afr afs aoa aoc aof aoo aor aos ar- ara arc arf aro arr ars as- asa asc asf aso asr ass c-- caa cac caf cao car cas cca ccc ccf cco ccr ccs cfa cfc cff cfo cfr cfs co- coa coc cof coo cor cos cra crc crf cro crr crs csa csc csf cso csr css faa fac faf fao far fas fca fcc fcf fco fcr fcs ffa ffc fff ffo ffr ffs foa foc fof foo for fos fra frc frf fro frr frs fsa fsc fsf fso fsr fss oaa oac oaf oao oar oas oc- oca occ ocf oco ocr ocs of- ofa ofc off ofo ofr ofs oo- ooa ooc oof ooo oor oos or- ora orc orf oro orr ors os- osa osc osf oso osr oss ra- raa rac raf rao rar ras rca rcc rcf rco rcr rcs rfa rfc rff rfo rfr rfs roa roc rof roo ror ros rra rrc rrf rrr rrs rsa rsc rsf rso rsr rss saa sac saf sao sar sas sca scc scf sco scr scs sfa sfc sff sfo sfr sfs soa soc sof soo sor sos sr- sra src srf sro srr srs ss- ssa ssc ssf sso ssr sss