a-a a-c a-t aaa aac aae aao aap aas aat aax ac- aca acc ace aco acp acs act acx aea aec aee aeo aep aes aet aex aoa aoc aoe aoo aop aos aot aox ap- apa apc ape apo app aps apt apx as- asa asc ase aso asp ass ast asx at- ata atc ate ato atp ats att atx ax- axa axe axo axp axs axt axx c-- caa cac cae cao cap cas cat cax cca ccc cce cco ccp ccs cct ccx ce- cea cec cee ceo cep ces cet cex co- coa coc coe coo cop cos cot cox cpa cpc cpe cpo cpp cps cpt cpx csa csc cse cso csp css cst csx cta ctc cte cto ctp cts ctt ctx cxc cxo cxp cxs cxt cxx eaa eac eae eao eap eas eat eax ec- eca ecc ece eco ecs ect ecx eea eec eee eeo eep ees eet eex eo- eoa eoc eoe eoo eop eos eot ep- epa epc epe epo epp eps ept epx es- esa esc ese eso esp ess est esx eta etc ete eto etp ets ett etx ex- exa exc exe exo exp exs ext exx oaa oac oae oao oap oas oat oax oc- oca occ oco ocp ocs oct ocx oea oec oee oeo oep oes oet oex oo- ooa ooc ooo oop oos oot oox op- opa opc ope opo opp ops opt opx os- osa osc ose oso osp oss ost osx ot- ota otc ote oto otp ots ott ox- oxa oxc oxo oxt oxx p-p paa pac pae pao pap pas pat pax pca pcc pce pco pcp pcs pct pcx pea pec pee peo pep pes pet pex poa poc poe poo pop pos pot pox ppa ppc ppe ppo ppp pps ppt ppx ps- psa psc pse pso psp pss pst psx pt- pta ptc pte pto ptp pts ptt ptx pxc pxe pxs pxt saa sac sae sao sap sas sat sax sca scc sce sco scp scs sct scx se- sea sec see seo sep ses set sex soa soc soe soo sop sos sot sox spa spc spe spo spp sps spt spx ss- ssa ssc sse sso ssp sss sst ssx sta stc ste sto stp sts stt stx sxc sxs sxt t-x taa tac tae tao tap tas tat tax tca tcc tce tco tcp tcs tct tcx te- tea tec tee teo tep tes tet tex to- toa toc toe too top tos tot tox tpa tpc tpe tpo tpp tps tpt tpx tsa tsc tse tso tsp tss tst tsx tta ttc tte tto ttp tts ttt ttx txe txs txt xaa xac xap xas xat xcp xcx xee xep xes xet xex xoa xoc xoo xop xos xot xox xpa xpc xpe xpo xpp xps xpt xsa xsc xsp xss xst xtc xtp xts xtx xxo xxp xxx