-er a-a a-b a-c a-t aaa aab aac aad aae aak aao aar aas aat ab- aba abb abc abd abe abk abo abr abs abt ac- aca acb acc acd ace ack aco acr acs act ad- ada adb adc add ade adk ado adr ads adt aea aeb aec aed aee aek aeo aer aes aet aka akb akc akd ake akk ako akr aks aoa aob aoc aod aoe aok aoo aor aos aot ar- ara arb arc ard are ark aro arr ars art as- asa asb asc asd ase ask aso asr ass ast at- ata atb atc atd ate ato atr ats att baa bab bac bad bae bak bao bar bas bat bba bbb bbc bbd bbe bbk bbo bbr bbs bbt bca bcb bcc bcd bce bck bco bcr bcs bct bda bdb bdc bdd bde bdk bdo bdr bds bdt be- bea beb bec bed bee bek beo ber bes bet bka bkb bkc bke bkk bko bkr bks bkt boa bob boc bod boe bok boo bor bos bot bra brb brd bre brk bro brr brs brt bsa bsb bsc bsd bse bsk bso bsr bss bst bta btb btc btd bte btk bto btr bts btt c-- caa cab cac cad cae cak cao car cas cat cba cbb cbc cbd cbe cbk cbo cbr cbs cbt cca ccb ccc ccd cce cck cco ccr ccs cct cda cdb cdc cdd cde cdk cdo cdr cds cdt ce- cea ceb cec ced cee cek ceo cer ces cet cka ckb ckc ckd cko cks ckt co- coa cob coc cod coe cok coo cor cos cot cra crb crc crd cre crk cro crr crs crt csa csb csc csd cse csk cso csr css cst cta ctb ctc ctd cte ctk cto ctr cts ctt daa dab dac dad dae dak dao dar das dat dba dbb dbc dbd dbe dbk dbo dbr dbs dbt dca dcb dcc dcd dce dck dco dcr dcs dct dda ddb ddc ddd dde ddk ddo ddr dds ddt de- dea deb dec ded dee dek deo der des det dka dkb dkc dke dkk dko dkr dks dkt doa dob doc dod doe dok doo dor dos dot dra drb drc drd dre drk dro drr drs drt dsa dsb dsc dsd dse dsk dso dsr dss dst dta dtb dtc dtd dte dtk dto dtr dts dtt eaa eab eac ead eae eak eao ear eas eat eba ebb ebc ebd ebe ebk ebo ebr ebs ebt ec- eca ecb ecc ecd ece eck eco ecr ecs ect ed- eda edb edc edd ede edk edo edr eds edt eea eeb eec eed eee eek eeo eer ees eet eka ekb ekc ekd eke eko ekr eks ekt eo- eoa eob eoc eod eoe eok eoo eor eos eot era erb erc erd ere erk ero err ers ert es- esa esb esc esd ese esk eso esr ess est eta etb etc etd ete etk eto etr ets ett k-t ka- kaa kab kac kad kae kak kao kar kas kat kba kbb kbc kbd kbe kbk kbo kbr kbs kca kcb kcc kcd kce kck kcr kcs kct kda kdb kdc kde kdk kdo kdr kds kdt ke- kea keb kec ked kee kek keo ker kes ket kkb kkc kke kkk kkr kks kkt koa kob koc kod koe kok koo kor kos kot kra krc krd krk kro krr krs krt ksa ksb ksc ksd kse ksk kso ksr kss kst kta ktb ktc kte ktk kto ktr kts ktt oaa oab oac oad oae oak oao oar oas oat ob- oba obb obc obd obe obk obo obr obs obt oc- oca ocb occ ocd ock oco ocr ocs oct oda odb odc odd ode odo odr ods odt oea oeb oec oed oee oeo oer oes oet oka okb okc okd oke okk oko okr oks oo- ooa oob ooc ood ook ooo oor oos oot or- ora orb orc ord ore ork oro orr ors ort os- osa osb osc osd ose osk oso osr oss ost ot- ota otb otc otd ote otk oto otr ots ott ra- raa rab rac rad rae rak rao rar ras rat rba rbb rbc rbd rbe rbk rbo rbr rbs rbt rca rcb rcc rcd rce rco rcr rcs rct rda rdb rdc rdd rde rdo rdr rds rdt re- rea reb rec red ree rek reo rer res ret rkb rkc rke rkk rko rks rkt roa rob roc rod roe rok roo ror ros rot rra rrb rrc rrd rrk rrr rrs rrt rsa rsb rsc rsd rse rsk rso rsr rss rst rta rtb rtc rtd rte rtk rto rtr rts rtt saa sab sac sad sae sak sao sar sas sat sba sbb sbc sbd sbe sbk sbo sbr sbs sbt sca scb scc scd sce sck sco scr scs sct sda sdb sdc sdd sde sdk sdo sdr sds sdt se- sea seb sec sed see sek seo ser ses set sk- ska skb skc skd ske skk sko skr sks skt soa sob soc sod soe sok soo sor sos sot sr- sra srb src srd sre srk sro srr srs srt ss- ssa ssb ssc ssd sse ssk sso ssr sss sst sta stb stc std ste stk sto str sts stt taa tab tac tad tae tak tao tar tas tat tba tbb tbc tbd tbe tbk tbo tbr tbs tbt tca tcb tcc tcd tce tck tco tcr tcs tct tda tdb tdc tdd tde tdk tdo tdr tds tdt te- tea teb tec ted tee tek teo ter tes tet tka tkb tkc tke tkk tko tkr tks tkt to- toa tob toc tod toe tok too tor tos tot tra trb trc trd tre trk tro trr trs trt tsa tsb tsc tsd tse tsk tso tsr tss tst tta ttb ttc ttd