-er a-a a-b a-t aaa aab aae aan aao aap aar aas aat ab- aba abb abe abn abo abp abr abs abt aea aeb aee aen aeo aep aer aes aet an- ana anb ane ann ano anp anr ans ant aoa aob aoe aon aoo aop aor aos aot ap- apa apb ape apn apo app apr aps apt ar- ara arb are arn aro arp arr ars art as- asa asb ase asn aso asp asr ass ast at- ata atb ate atn ato atp atr ats att b-p baa bab bae ban bao bap bar bas bat bba bbb bbe bbn bbo bbp bbr bbs bbt be- bea beb bee ben beo bep ber bes bet bna bnb bne bnn bno bnp bnr bns bnt boa bob boe bon boo bop bor bos bot bpa bpb bpe bpn bpo bpp bpr bps bpt bra brb bre brn bro brp brr brs brt bsa bsb bse bsn bso bsp bsr bss bst bta btb bte btn bto btp btr bts btt eaa eab eae ean eao eap ear eas eat eba ebb ebe ebn ebo ebp ebr ebs ebt eea eeb eee een eeo eep eer ees eet en- ena enb ene enn eno enp enr ens ent eo- eoa eob eoe eon eoo eop eor eos eot ep- epa epb epe epn epo epp epr eps ept era erb ere ern ero erp err ers ert es- esa esb ese esn eso esp esr ess est eta etb ete etn eto etp etr ets ett naa nab nae nan nao nap nar nas nat nba nbb nbe nbn nbo nbp nbr nbs nbt ne- nea neb nee nen neo nep ner nes net nna nnb nne nnn nno nnp nns nnt no- noa nob noe non noo nop nor nos not npa npb npe npn npo npp npr nps npt nra nrb nre nrn nro nrp nrr nrs nrt nsa nsb nse nsn nso nsp nsr nss nst nta ntb nte ntn nto ntp ntr nts ntt oaa oab oae oan oao oap oar oas oat ob- oba obb obe obn obo obp obr obs obt oea oeb oee oen oeo oep oer oes oet on- ona onb one onn ono onp onr ons ont oo- ooa oob oon ooo oop oor oos oot op- opa opb ope opn opo opp opr ops opt or- ora orb ore orn oro orp orr ors ort os- osa osb ose osn oso osp osr oss ost ot- ota otb ote otn oto otp otr ots ott p-p paa pab pae pan pao pap par pas pat pba pbb pbe pbn pbo pbp pbr pbs pbt pea peb pee pen peo pep per pes pet pn- pna pnb pne pnn pno pnp pnr pns pnt poa pob poe pon poo pop por pos pot ppa ppb ppe ppn ppo ppp ppr pps ppt pra prb pre prn pro prp prr prs prt ps- psa psb pse psn pso psp psr pss pst pt- pta ptb pte ptn pto ptp ptr pts ptt ra- raa rab rae ran rao rap rar ras rat rba rbb rbe rbn rbo rbp rbr rbs rbt re- rea reb ree ren reo rep rer res ret rna rnb rnn rno rnp rnr rns rnt roa rob roe ron roo rop ror ros rot rpa rpb rpe rpn rpo rpp rpr rps rpt rra rrb rrn rrp rrr rrs rrt rsa rsb rse rsn rso rsp rsr rss rst rta rtb rte rtn rto rtp rtr rts rtt saa sab sae san sao sap sar sas sat sba sbb sbe sbn sbo sbp sbr sbs sbt se- sea seb see sen seo sep ser ses set sna snb sne snn sno snp snr sns snt soa sob soe son soo sop sor sos sot spa spb spe spn spo spp spr sps spt sr- sra srb sre srn sro srp srr srs srt ss- ssa ssb sse ssn sso ssp ssr sss sst sta stb ste stn sto stp str sts stt taa tab tae tan tao tap tar tas tat tba tbb tbe tbn tbo tbp tbr tbs tbt te- tea teb tee ten teo tep ter tes tet tna tnb tne tnn tno tnp tnr tns tnt to- toa tob toe ton too top tor tos tot tpa tpb tpe tpn tpo tpp tpr tps tpt tra trb tre trn tro trp trr trs trt tsa tsb tse tsn tso tsp tsr tss tst tta ttb tte ttn tto ttp ttr tts ttt