-er a-a a-c a-t aaa aac aae aaf aap aar aat aax ac- aca acc ace acf acp acr act acx aea aec aee aef aep aer aet aex af- afa afc afe aff afp afr aft afx ap- apa apc ape apf app apr apt apx ar- ara arc are arf arp arr art arx at- ata atc ate atf atp atr att atx ax- axa axe axp axr axt axx c-- caa cac cae caf cap car cat cax cca ccc cce ccf ccp ccr cct ccx ce- cea cec cee cef cep cer cet cex cfa cfc cfe cff cfp cfr cft cfx cpa cpc cpe cpf cpp cpr cpt cpx cra crc cre crf crp crr crt crx cta ctc cte ctf ctp ctr ctt ctx cxc cxf cxp cxr cxt cxx eaa eac eae eaf eap ear eat eax ec- eca ecc ece ecf ecr ect ecx eea eec eee eef eep eer eet eex ef- efa efc efe eff efp efr eft efx ep- epa epc epe epf epp epr ept epx era erc ere erf erp err ert eta etc ete etf etp etr ett etx ex- exa exc exe exp exr ext exx faa fac fae faf fap far fat fax fca fcc fce fcf fcp fcr fct fcx fea fec fee fef fep fer fet fex ffa ffc ffe fff ffp ffr fft ffx fpa fpc fpe fpp fpr fpt fpx fra frc fre frf frp frr frt fta ftc fte ftf ftp ftr ftt ftx fxe fxp fxr fxt fxx p-p paa pac pae paf pap par pat pax pca pcc pce pcf pcp pcr pct pcx pea pec pee pef pep per pet pex pfa pfc pfe pff pfp pfr pft pfx ppa ppc ppe ppf ppp ppr ppt ppx pra prc pre prf prp prr prt prx pt- pta ptc pte ptf ptp ptr ptt ptx pxc pxe pxr pxt ra- raa rac rae raf rap rar rat rax rca rcc rce rcf rcp rcr rct rcx re- rea rec ree ref rep rer ret rex rfa rfc rfe rff rfp rfr rft rpa rpc rpe rpf rpp rpr rpt rpx rra rrc rrf rrp rrr rrt rta rtc rte rtf rtp rtr rtt rtx rxp rxr t-x taa tac tae taf tap tar tat tax tca tcc tce tcf tcp tcr tct tcx te- tea tec tee tef tep ter tet tex tfa tfc tfe tff tfp tfr tft tfx tpa tpc tpe tpf tpp tpr tpt tpx tra trc tre trf trp trr trt trx tta ttc tte ttf ttp ttr ttt ttx txe txf txt xaa xac xaf xap xar xat xcf xcp xcr xcx xee xep xer xet xex xfa xfe xft xfx xpa xpc xpe xpf xpp xpt xrc xrf xrt xrx xtc xtf xtp xtr xtx xxp xxx