a-a a-c a-t aaa aac aae aap aas aat ac- aca acc ace acp acs act aea aec aee aep aes aet ap- apa apc ape app aps apt as- asa asc ase asp ass ast at- ata atc ate atp ats att c-- caa cac cae cap cas cat cca ccc cce ccp ccs cct ce- cea cec cee cep ces cet cpa cpc cpe cpp cps cpt csa csc cse csp css cst cta ctc cte ctp cts ctt eaa eac eae eap eas eat ec- eca ecc ece ecs ect eea eec eee eep ees eet ep- epa epc epe epp eps ept es- esa esc ese esp ess est eta etc ete etp ets ett p-p paa pac pae pap pas pat pca pcc pce pcp pcs pct pea pec pee pep pes pet ppa ppc ppe ppp pps ppt ps- psa psc pse psp pss pst pt- pta ptc pte ptp pts ptt saa sac sae sap sas sat sca scc sce scp scs sct se- sea sec see sep ses set spa spc spe spp sps spt ss- ssa ssc sse ssp sss sst sta stc ste stp sts stt taa tac tae tap tas tat tca tcc tce tcp tcs tct te- tea tec tee tep tes tet tpa tpc tpe tpp tps tpt tsa tsc tse tsp tss tst tta ttc tte ttp tts ttt