a-a a-c a-t aaa aac aae aan aap aas aat aax ac- aca acc ace acn acp acs act acx aea aec aee aen aep aes aet aex an- ana anc ane ann anp ans ant anx ap- apa apc ape apn app aps apt apx as- asa asc ase asn asp ass ast asx at- ata atc ate atn atp ats att atx ax- axa axe axn axp axs axt axx c-- caa cac cae can cap cas cat cax cca ccc cce ccn ccp ccs cct ccx ce- cea cec cee cen cep ces cet cex cn- cna cnc cne cnn cnp cns cnt cnx cpa cpc cpe cpn cpp cps cpt cpx csa csc cse csn csp css cst csx cta ctc cte ctn ctp cts ctt ctx cxc cxp cxs cxt cxx eaa eac eae ean eap eas eat eax ec- eca ecc ece ecn ecs ect ecx eea eec eee een eep ees eet eex en- ena enc ene enn enp ens ent ep- epa epc epe epn epp eps ept epx es- esa esc ese esn esp ess est esx eta etc ete etn etp ets ett etx ex- exa exc exe exp exs ext exx naa nac nae nan nap nas nat nax nca ncc nce ncn ncp ncs nct ncx ne- nea nec nee nen nep nes net nex nna nnc nne nnn nnp nns nnt npa npc npe npn npp nps npt nsa nsc nse nsn nsp nss nst nsx nta ntc nte ntn ntp nts ntt ntx nxc nxt p-p paa pac pae pan pap pas pat pax pca pcc pce pcn pcp pcs pct pcx pea pec pee pen pep pes pet pex pn- pna pnc pne pnn pnp pns pnt pnx ppa ppc ppe ppn ppp pps ppt ppx ps- psa psc pse psn psp pss pst psx pt- pta ptc pte ptn ptp pts ptt ptx pxc pxe pxs pxt saa sac sae san sap sas sat sax sca scc sce scn scp scs sct scx se- sea sec see sen sep ses set sex sna snc sne snn snp sns snt spa spc spe spn spp sps spt spx ss- ssa ssc sse ssn ssp sss sst ssx sta stc ste stn stp sts stt stx sxc sxn sxs sxt t-x taa tac tae tan tap tas tat tax tca tcc tce tcn tcp tcs tct tcx te- tea tec tee ten tep tes tet tex tna tnc tne tnn tnp tns tnt tnx tpa tpc tpe tpn tpp tps tpt tpx tsa tsc tse tsn tsp tss tst tsx tta ttc tte ttn ttp tts ttt ttx txe txn txs txt xaa xac xan xap xas xat xcp xcx xee xen xep xes xet xex xna xnc xns xpa xpc xpe xpn xpp xps xpt xsa xsc xsp xss xst xtc xtp xts xtx xxp xxx