-er a-a a-c a-t aaa aac aae aao aap aar aat aax ac- aca acc ace aco acp acr act acx aea aec aee aeo aep aer aet aex aoa aoc aoe aoo aop aor aot aox ap- apa apc ape apo app apr apt apx ar- ara arc are aro arp arr art arx at- ata atc ate ato atp atr att atx ax- axa axe axo axp axr axt axx c-- caa cac cae cao cap car cat cax cca ccc cce cco ccp ccr cct ccx ce- cea cec cee ceo cep cer cet cex co- coa coc coe coo cop cor cot cox cpa cpc cpe cpo cpp cpr cpt cpx cra crc cre cro crp crr crt crx cta ctc cte cto ctp ctr ctt ctx cxc cxo cxp cxr cxt cxx eaa eac eae eao eap ear eat eax ec- eca ecc ece eco ecr ect ecx eea eec eee eeo eep eer eet eex eo- eoa eoc eoe eoo eop eor eot ep- epa epc epe epo epp epr ept epx era erc ere ero erp err ert eta etc ete eto etp etr ett etx ex- exa exc exe exo exp exr ext exx oaa oac oae oao oap oar oat oax oc- oca occ oco ocp ocr oct ocx oea oec oee oeo oep oer oet oex oo- ooa ooc ooo oop oor oot oox op- opa opc ope opo opp opr opt opx or- ora orc ore oro orp orr ort orx ot- ota otc ote oto otp otr ott ox- oxa oxc oxo oxt oxx p-p paa pac pae pao pap par pat pax pca pcc pce pco pcp pcr pct pcx pea pec pee peo pep per pet pex poa poc poe poo pop por pot pox ppa ppc ppe ppo ppp ppr ppt ppx pra prc pre pro prp prr prt prx pt- pta ptc pte pto ptp ptr ptt ptx pxc pxe pxr pxt ra- raa rac rae rao rap rar rat rax rca rcc rce rco rcp rcr rct rcx re- rea rec ree reo rep rer ret rex roa roc roe roo rop ror rot rox rpa rpc rpe rpo rpp rpr rpt rpx rra rrc rrp rrr rrt rta rtc rte rto rtp rtr rtt rtx rxp rxr t-x taa tac tae tao tap tar tat tax tca tcc tce tco tcp tcr tct tcx te- tea tec tee teo tep ter tet tex to- toa toc toe too top tor tot tox tpa tpc tpe tpo tpp tpr tpt tpx tra trc tre tro trp trr trt trx tta ttc tte tto ttp ttr ttt ttx txe txt xaa xac xap xar xat xcp xcr xcx xee xep xer xet xex xoa xoc xoo xop xor xot xox xpa xpc xpe xpo xpp xpt xrc xrt xrx xtc xtp xtr xtx xxo xxp xxx