-er a-a a-c a-t aaa aac aae aao aap aar aas aat aax ac- aca acc ace aco acp acr acs act acx aea aec aee aeo aep aer aes aet aex aoa aoc aoe aoo aop aor aos aot aox ap- apa apc ape apo app apr aps apt apx ar- ara arc are aro arp arr ars art arx as- asa asc ase aso asp asr ass ast asx at- ata atc ate ato atp atr ats att atx ax- axa axe axo axp axr axs axt axx c-- caa cac cae cao cap car cas cat cax cca ccc cce cco ccp ccr ccs cct ccx ce- cea cec cee ceo cep cer ces cet cex co- coa coc coe coo cop cor cos cot cox cpa cpc cpe cpo cpp cpr cps cpt cpx cra crc cre cro crp crr crs crt crx csa csc cse cso csp csr css cst csx cta ctc cte cto ctp ctr cts ctt ctx cxc cxo cxp cxr cxs cxt cxx eaa eac eae eao eap ear eas eat eax ec- eca ecc ece eco ecr ecs ect ecx eea eec eee eeo eep eer ees eet eex eo- eoa eoc eoe eoo eop eor eos eot ep- epa epc epe epo epp epr eps ept epx era erc ere ero erp err ers ert es- esa esc ese eso esp esr ess est esx eta etc ete eto etp etr ets ett etx ex- exa exc exe exo exp exr exs ext exx oaa oac oae oao oap oar oas oat oax oc- oca occ oco ocp ocr ocs oct ocx oea oec oee oeo oep oer oes oet oex oo- ooa ooc ooo oop oor oos oot oox op- opa opc ope opo opp opr ops opt opx or- ora orc ore oro orp orr ors ort orx os- osa osc ose oso osp osr oss ost osx ot- ota otc ote oto otp otr ots ott ox- oxa oxc oxo oxt oxx p-p paa pac pae pao pap par pas pat pax pca pcc pce pco pcp pcr pcs pct pcx pea pec pee peo pep per pes pet pex poa poc poe poo pop por pos pot pox ppa ppc ppe ppo ppp ppr pps ppt ppx pra prc pre pro prp prr prs prt prx ps- psa psc pse pso psp psr pss pst psx pt- pta ptc pte pto ptp ptr pts ptt ptx pxc pxe pxr pxs pxt ra- raa rac rae rao rap rar ras rat rax rca rcc rce rco rcp rcr rcs rct rcx re- rea rec ree reo rep rer res ret rex roa roc roe roo rop ror ros rot rox rpa rpc rpe rpo rpp rpr rps rpt rpx rra rrc rrp rrr rrs rrt rsa rsc rse rso rsp rsr rss rst rsx rta rtc rte rto rtp rtr rts rtt rtx rxp rxr rxs saa sac sae sao sap sar sas sat sax sca scc sce sco scp scr scs sct scx se- sea sec see seo sep ser ses set sex soa soc soe soo sop sor sos sot sox spa spc spe spo spp spr sps spt spx sr- sra src sre sro srp srr srs srt srx ss- ssa ssc sse sso ssp ssr sss sst ssx sta stc ste sto stp str sts stt stx sxc sxs sxt t-x taa tac tae tao tap tar tas tat tax tca tcc tce tco tcp tcr tcs tct tcx te- tea tec tee teo tep ter tes tet tex to- toa toc toe too top tor tos tot tox tpa tpc tpe tpo tpp tpr tps tpt tpx tra trc tre tro trp trr trs trt trx tsa tsc tse tso tsp tsr tss tst tsx tta ttc tte tto ttp ttr tts ttt ttx txe txs txt xaa xac xap xar xas xat xcp xcr xcx xee xep xer xes xet xex xoa xoc xoo xop xor xos xot xox xpa xpc xpe xpo xpp xps xpt xrc xrt xrx xsa xsc xsp xss xst xtc xtp xtr xts xtx xxo xxp xxx