a-a aaa aaf aan aao aar aas af- afa aff afn afo afr afs an- ana anf ann ano anr ans aoa aof aon aoo aor aos ar- ara arf arn aro arr ars as- asa asf asn aso asr ass faa faf fan fao far fas ffa fff ffn ffo ffr ffs fna fnf fnn fnr fns foa fof fon foo for fos fra frf frn fro frr frs fsa fsf fsn fso fsr fss naa naf nan nao nar nas nfa nff nfn nfo nfr nfs nna nnf nnn nno nns no- noa nof non noo nor nos nra nrf nrn nro nrr nrs nsa nsf nsn nso nsr nss oaa oaf oan oao oar oas of- ofa off ofn ofo ofr ofs on- ona onf onn ono onr ons oo- ooa oof oon ooo oor oos or- ora orf orn oro orr ors os- osa osf osn oso osr oss ra- raa raf ran rao rar ras rfa rff rfn rfo rfr rfs rna rnn rno rnr rns roa rof ron roo ror ros rra rrf rrn rrr rrs rsa rsf rsn rso rsr rss saa saf san sao sar sas sfa sff sfn sfo sfr sfs sna snf snn sno snr sns soa sof son soo sor sos sr- sra srf srn sro srr srs ss- ssa ssf ssn sso ssr sss