a-a a-c aaa aac aaf aan aao aar aas ac- aca acc acf acn aco acr acs af- afa afc aff afn afo afr afs an- ana anc anf ann ano anr ans aoa aoc aof aon aoo aor aos ar- ara arc arf arn aro arr ars as- asa asc asf asn aso asr ass c-- caa cac caf can cao car cas cca ccc ccf ccn cco ccr ccs cfa cfc cff cfn cfo cfr cfs cn- cna cnc cnf cnn cno cnr cns co- coa coc cof con coo cor cos cra crc crf crn cro crr crs csa csc csf csn cso csr css faa fac faf fan fao far fas fca fcc fcf fcn fco fcr fcs ffa ffc fff ffn ffo ffr ffs fna fnc fnf fnn fnr fns foa foc fof fon foo for fos fra frc frf frn fro frr frs fsa fsc fsf fsn fso fsr fss naa nac naf nan nao nar nas nca ncc ncf ncn nco ncr ncs nfa nfc nff nfn nfo nfr nfs nna nnc nnf nnn nno nns no- noa noc nof non noo nor nos nra nrc nrf nrn nro nrr nrs nsa nsc nsf nsn nso nsr nss oaa oac oaf oan oao oar oas oc- oca occ ocf ocn oco ocr ocs of- ofa ofc off ofn ofo ofr ofs on- ona onc onf onn ono onr ons oo- ooa ooc oof oon ooo oor oos or- ora orc orf orn oro orr ors os- osa osc osf osn oso osr oss ra- raa rac raf ran rao rar ras rca rcc rcf rcn rco rcr rcs rfa rfc rff rfn rfo rfr rfs rna rnc rnn rno rnr rns roa roc rof ron roo ror ros rra rrc rrf rrn rrr rrs rsa rsc rsf rsn rso rsr rss saa sac saf san sao sar sas sca scc scf scn sco scr scs sfa sfc sff sfn sfo sfr sfs sna snc snf snn sno snr sns soa soc sof son soo sor sos sr- sra src srf srn sro srr srs ss- ssa ssc ssf ssn sso ssr sss