a-a a-c aaa aac aan aao aar aas ac- aca acc acn aco acr acs an- ana anc ann ano anr ans aoa aoc aon aoo aor aos ar- ara arc arn aro arr ars as- asa asc asn aso asr ass c-- caa cac can cao car cas cca ccc ccn cco ccr ccs cn- cna cnc cnn cno cnr cns co- coa coc con coo cor cos cra crc crn cro crr crs csa csc csn cso csr css naa nac nan nao nar nas nca ncc ncn nco ncr ncs nna nnc nnn nno nns no- noa noc non noo nor nos nra nrc nrn nro nrr nrs nsa nsc nsn nso nsr nss oaa oac oan oao oar oas oc- oca occ ocn oco ocr ocs on- ona onc onn ono onr ons oo- ooa ooc oon ooo oor oos or- ora orc orn oro orr ors os- osa osc osn oso osr oss ra- raa rac ran rao rar ras rca rcc rcn rco rcr rcs rna rnc rnn rno rnr rns roa roc ron roo ror ros rra rrc rrn rrr rrs rsa rsc rsn rso rsr rss saa sac san sao sar sas sca scc scn sco scr scs sna snc snn sno snr sns soa soc son soo sor sos sr- sra src srn sro srr srs ss- ssa ssc ssn sso ssr sss