a-a a-c a-t aaa aac aaf aar aas aat ac- aca acc acf acr acs act af- afa afc aff afr afs aft ar- ara arc arf arr ars art as- asa asc asf asr ass ast at- ata atc atf atr ats att c-- caa cac caf car cas cat cca ccc ccf ccr ccs cct cfa cfc cff cfr cfs cft cra crc crf crr crs crt csa csc csf csr css cst cta ctc ctf ctr cts ctt faa fac faf far fas fat fca fcc fcf fcr fcs fct ffa ffc fff ffr ffs fft fra frc frf frr frs frt fsa fsc fsf fsr fss fst fta ftc ftf ftr fts ftt ra- raa rac raf rar ras rat rca rcc rcf rcr rcs rct rfa rfc rff rfr rfs rft rra rrc rrf rrr rrs rrt rsa rsc rsf rsr rss rst rta rtc rtf rtr rts rtt saa sac saf sar sas sat sca scc scf scr scs sct sfa sfc sff sfr sfs sft sr- sra src srf srr srs srt ss- ssa ssc ssf ssr sss sst sta stc stf str sts stt taa tac taf tar tas tat tca tcc tcf tcr tcs tct tfa tfc tff tfr tfs tft tra trc trf trr trs trt tsa tsc tsf tsr tss tst tta ttc ttf ttr tts ttt