a-a a-c a-t aaa aac aar aat aay ac- aca acc acr act acy ar- ara arc arr art ary at- ata atc atr att ay- aya ayc ayr ayt c-- caa cac car cat cay cca ccc ccr cct cra crc crr crt cry cta ctc ctr ctt cty cya cyc cyr cyt ra- raa rac rar rat ray rca rcc rcr rct rra rrc rrr rrt rta rtc rtr rtt rty ry- rya ryc ryr ryy taa tac tar tat tay tca tcc tcr tct tra trc trr trt try tta ttc ttr ttt tty tya tyc tyr tyt yaa yac yar yat yay yca ycc ycy yra yrc yrt yta ytc ytr ytt yyc yyt yyy