-er a-a a-b a-t aaa aab aae aao aap aar aas aat aax ab- aba abb abe abo abp abr abs abt abx aea aeb aee aeo aep aer aes aet aex aoa aob aoe aoo aop aor aos aot aox ap- apa apb ape apo app apr aps apt apx ar- ara arb are aro arp arr ars art arx as- asa asb ase aso asp asr ass ast asx at- ata atb ate ato atp atr ats att atx ax- axa axe axo axp axr axs axt axx b-p baa bab bae bao bap bar bas bat bax bba bbb bbe bbo bbp bbr bbs bbt bbx be- bea beb bee beo bep ber bes bet bex boa bob boe boo bop bor bos bot box bpa bpb bpe bpo bpp bpr bps bpt bpx bra brb bre bro brp brr brs brt brx bsa bsb bse bso bsp bsr bss bst bsx bta btb bte bto btp btr bts btt btx bxb bxo bxx eaa eab eae eao eap ear eas eat eax eba ebb ebe ebo ebp ebr ebs ebt ebx eea eeb eee eeo eep eer ees eet eex eo- eoa eob eoe eoo eop eor eos eot ep- epa epb epe epo epp epr eps ept epx era erb ere ero erp err ers ert es- esa esb ese eso esp esr ess est esx eta etb ete eto etp etr ets ett etx ex- exa exe exo exp exr exs ext exx oaa oab oae oao oap oar oas oat oax ob- oba obb obe obo obp obr obs obt obx oea oeb oee oeo oep oer oes oet oex oo- ooa oob ooo oop oor oos oot oox op- opa opb ope opo opp opr ops opt opx or- ora orb ore oro orp orr ors ort orx os- osa osb ose oso osp osr oss ost osx ot- ota otb ote oto otp otr ots ott ox- oxa oxb oxo oxt oxx p-p paa pab pae pao pap par pas pat pax pba pbb pbe pbo pbp pbr pbs pbt pbx pea peb pee peo pep per pes pet pex poa pob poe poo pop por pos pot pox ppa ppb ppe ppo ppp ppr pps ppt ppx pra prb pre pro prp prr prs prt prx ps- psa psb pse pso psp psr pss pst psx pt- pta ptb pte pto ptp ptr pts ptt ptx pxe pxr pxs pxt ra- raa rab rae rao rap rar ras rat rax rba rbb rbe rbo rbp rbr rbs rbt rbx re- rea reb ree reo rep rer res ret rex roa rob roe roo rop ror ros rot rox rpa rpb rpe rpo rpp rpr rps rpt rpx rra rrb rrp rrr rrs rrt rsa rsb rse rso rsp rsr rss rst rsx rta rtb rte rto rtp rtr rts rtt rtx rxp rxr rxs saa sab sae sao sap sar sas sat sax sba sbb sbe sbo sbp sbr sbs sbt sbx se- sea seb see seo sep ser ses set sex soa sob soe soo sop sor sos sot sox spa spb spe spo spp spr sps spt spx sr- sra srb sre sro srp srr srs srt srx ss- ssa ssb sse sso ssp ssr sss sst ssx sta stb ste sto stp str sts stt stx sxs sxt t-x taa tab tae tao tap tar tas tat tax tba tbb tbe tbo tbp tbr tbs tbt te- tea teb tee teo tep ter tes tet tex to- toa tob toe too top tor tos tot tox tpa tpb tpe tpo tpp tpr tps tpt tpx tra trb tre tro trp trr trs trt trx tsa tsb tse tso tsp tsr tss tst tsx tta ttb tte tto ttp ttr tts ttt ttx txe txs txt xaa xap xar xas xat xbe xbr xbx xee xep xer xes xet xex xoa xoo xop xor xos xot xox xpa xpb xpe xpo xpp xps xpt xrt xrx xsa xsb xsp xss xst xtp xtr xts xtx xxo xxp xxx