-er a-a a-b a-t aaa aab aae aak aan aao aar aas aat ab- aba abb abe abk abn abo abr abs abt aea aeb aee aek aen aeo aer aes aet aka akb ake akk akn ako akr aks an- ana anb ane ank ann ano anr ans ant aoa aob aoe aok aon aoo aor aos aot ar- ara arb are ark arn aro arr ars art as- asa asb ase ask asn aso asr ass ast at- ata atb ate atn ato atr ats att baa bab bae bak ban bao bar bas bat bba bbb bbe bbk bbn bbo bbr bbs bbt be- bea beb bee bek ben beo ber bes bet bka bkb bke bkk bkn bko bkr bks bkt bna bnb bne bnk bnn bno bnr bns bnt boa bob boe bok bon boo bor bos bot bra brb bre brk brn bro brr brs brt bsa bsb bse bsk bsn bso bsr bss bst bta btb bte btk btn bto btr bts btt eaa eab eae eak ean eao ear eas eat eba ebb ebe ebk ebn ebo ebr ebs ebt eea eeb eee eek een eeo eer ees eet eka ekb eke eko ekr eks ekt en- ena enb ene enk enn eno enr ens ent eo- eoa eob eoe eok eon eoo eor eos eot era erb ere erk ern ero err ers ert es- esa esb ese esk esn eso esr ess est eta etb ete etk etn eto etr ets ett k-t ka- kaa kab kae kak kan kao kar kas kat kba kbb kbe kbk kbn kbo kbr kbs ke- kea keb kee kek ken keo ker kes ket kkb kke kkk kkn kkr kks kkt kn- kna kne knk knn kno knr knt koa kob koe kok kon koo kor kos kot kra krk krn kro krr krs krt ksa ksb kse ksk ksn kso ksr kss kst kta ktb kte ktk ktn kto ktr kts ktt naa nab nae nak nan nao nar nas nat nba nbb nbe nbk nbn nbo nbr nbs nbt ne- nea neb nee nek nen neo ner nes net nka nke nkk nkn nko nkr nks nkt nna nnb nne nnk nnn nno nns nnt no- noa nob noe nok non noo nor nos not nra nrb nre nrk nrn nro nrr nrs nrt nsa nsb nse nsk nsn nso nsr nss nst nta ntb nte ntk ntn nto ntr nts ntt oaa oab oae oak oan oao oar oas oat ob- oba obb obe obk obn obo obr obs obt oea oeb oee oen oeo oer oes oet oka okb oke okk oko okr oks on- ona onb one onk onn ono onr ons ont oo- ooa oob ook oon ooo oor oos oot or- ora orb ore ork orn oro orr ors ort os- osa osb ose osk osn oso osr oss ost ot- ota otb ote otk otn oto otr ots ott ra- raa rab rae rak ran rao rar ras rat rba rbb rbe rbk rbn rbo rbr rbs rbt re- rea reb ree rek ren reo rer res ret rkb rke rkk rko rks rkt rna rnb rnn rno rnr rns rnt roa rob roe rok ron roo ror ros rot rra rrb rrk rrn rrr rrs rrt rsa rsb rse rsk rsn rso rsr rss rst rta rtb rte rtk rtn rto rtr rts rtt saa sab sae sak san sao sar sas sat sba sbb sbe sbk sbn sbo sbr sbs sbt se- sea seb see sek sen seo ser ses set sk- ska skb ske skk sko skr sks skt sna snb sne snk snn sno snr sns snt soa sob soe sok son soo sor sos sot sr- sra srb sre srk srn sro srr srs srt ss- ssa ssb sse ssk ssn sso ssr sss sst sta stb ste stk stn sto str sts stt taa tab tae tak tan tao tar tas tat tba tbb tbe tbk tbn tbo tbr tbs tbt te- tea teb tee tek ten teo ter tes tet tka tkb tke tkk tko tkr tks tkt tna tnb tne tnk tnn tno tnr tns tnt to- toa tob toe tok ton too tor tos tot tra trb tre trk trn tro trr trs trt tsa tsb tse tsk tsn tso tsr tss tst tta ttb tte ttk ttn tto ttr tts ttt