a-a a-c a-t aaa aac aas aat aay ac- aca acc acs act acy as- asa asc ass ast asy at- ata atc ats att ay- aya ayc ays ayt c-- caa cac cas cat cay cca ccc ccs cct csa csc css cst csy cta ctc cts ctt cty cya cyc cys cyt saa sac sas sat say sca scc scs sct ss- ssa ssc sss sst sta stc sts stt sty sy- sya syc sys syt taa tac tas tat tay tca tcc tcs tct tsa tsc tss tst tsy tta ttc tts ttt tty tya tyc tys tyt yaa yac yas yat yay yca ycc ycs ycy ysa ysc yss yst ysy yta ytc yts ytt yyc yys yyt yyy