a-a a-c a-t aaa aac aaf aar aat ac- aca acc acf acr act af- afa afc aff afr aft ar- ara arc arf arr art at- ata atc atf atr att c-- caa cac caf car cat cca ccc ccf ccr cct cfa cfc cff cfr cft cra crc crf crr crt cta ctc ctf ctr ctt faa fac faf far fat fca fcc fcf fcr fct ffa ffc fff ffr fft fra frc frf frr frt fta ftc ftf ftr ftt ra- raa rac raf rar rat rca rcc rcf rcr rct rfa rfc rff rfr rft rra rrc rrf rrr rrt rta rtc rtf rtr rtt taa tac taf tar tat tca tcc tcf tcr tct tfa tfc tff tfr tft tra trc trf trr trt tta ttc ttf ttr ttt