a-a a-c aaa aac aaf aan aar aas ac- aca acc acf acn acr acs af- afa afc aff afn afr afs an- ana anc anf ann anr ans ar- ara arc arf arn arr ars as- asa asc asf asn asr ass c-- caa cac caf can car cas cca ccc ccf ccn ccr ccs cfa cfc cff cfn cfr cfs cn- cna cnc cnf cnn cnr cns cra crc crf crn crr crs csa csc csf csn csr css faa fac faf fan far fas fca fcc fcf fcn fcr fcs ffa ffc fff ffn ffr ffs fna fnc fnf fnn fnr fns fra frc frf frn frr frs fsa fsc fsf fsn fsr fss naa nac naf nan nar nas nca ncc ncf ncn ncr ncs nfa nfc nff nfn nfr nfs nna nnc nnf nnn nns nra nrc nrf nrn nrr nrs nsa nsc nsf nsn nsr nss ra- raa rac raf ran rar ras rca rcc rcf rcn rcr rcs rfa rfc rff rfn rfr rfs rna rnc rnn rnr rns rra rrc rrf rrn rrr rrs rsa rsc rsf rsn rsr rss saa sac saf san sar sas sca scc scf scn scr scs sfa sfc sff sfn sfr sfs sna snc snf snn snr sns sr- sra src srf srn srr srs ss- ssa ssc ssf ssn ssr sss