-er a-a a-b a-c a-t aaa aab aac aae aag aak aao aar aas aat ab- aba abb abc abe abg abk abo abr abs abt ac- aca acb acc ace acg ack aco acr acs act aea aeb aec aee aeg aek aeo aer aes aet ag- aga agb agc age agg agk ago agr ags agt aka akb akc ake akg akk ako akr aks aoa aob aoc aoe aog aok aoo aor aos aot ar- ara arb arc are arg ark aro arr ars art as- asa asb asc ase asg ask aso asr ass ast at- ata atb atc ate atg ato atr ats att baa bab bac bae bag bak bao bar bas bat bba bbb bbc bbe bbg bbk bbo bbr bbs bbt bca bcb bcc bce bcg bck bco bcr bcs bct be- bea beb bec bee beg bek beo ber bes bet bga bgb bgc bge bgg bgk bgo bgr bgs bgt bka bkb bkc bke bkg bkk bko bkr bks bkt boa bob boc boe bog bok boo bor bos bot bra brb bre brg brk bro brr brs brt bsa bsb bsc bse bsg bsk bso bsr bss bst bta btb btc bte btg btk bto btr bts btt c-- caa cab cac cae cag cak cao car cas cat cba cbb cbc cbe cbg cbk cbo cbr cbs cbt cca ccb ccc cce ccg cck cco ccr ccs cct ce- cea ceb cec cee ceg cek ceo cer ces cet cga cgb cgc cge cgg cgo cgr cgs cgt cka ckb ckc cko cks ckt co- coa cob coc coe cog cok coo cor cos cot cra crb crc cre crg crk cro crr crs crt csa csb csc cse csg csk cso csr css cst cta ctb ctc cte ctg ctk cto ctr cts ctt eaa eab eac eae eag eak eao ear eas eat eba ebb ebc ebe ebg ebk ebo ebr ebs ebt ec- eca ecb ecc ece ecg eck eco ecr ecs ect eea eeb eec eee eeg eek eeo eer ees eet ega egb egc ege egg ego egr egs egt eka ekb ekc eke ekg eko ekr eks ekt eo- eoa eob eoc eoe eog eok eoo eor eos eot era erb erc ere erg erk ero err ers ert es- esa esb esc ese esg esk eso esr ess est eta etb etc ete etg etk eto etr ets ett gaa gab gac gae gag gak gao gar gas gat gba gbc gbe gbg gbk gbo gbr gbs gbt gca gcb gcc gce gcg gck gco gcr gcs gct ge- gea geb gec gee geg gek geo ger ges get gga ggb ggc ggg ggo ggr ggs ggt gka gkb gko gks gkt goa gob goc goe gog gok goo gor gos got gra grb grc gre grg grk gro grr grs grt gsa gsb gsc gse gsg gsk gso gsr gss gst gta gtb gtc gte gtg gtk gto gtr gts gtt k-t ka- kaa kab kac kae kag kak kao kar kas kat kba kbb kbc kbe kbk kbo kbr kbs kca kcb kcc kce kcg kck kcr kcs kct ke- kea keb kec kee keg kek keo ker kes ket kga kgb kgc kgo kgs kkb kkc kke kkk kkr kks kkt koa kob koc koe kog kok koo kor kos kot kra krc krg krk kro krr krs krt ksa ksb ksc kse ksg ksk kso ksr kss kst kta ktb ktc kte ktg ktk kto ktr kts ktt oaa oab oac oae oag oak oao oar oas oat ob- oba obb obc obe obg obk obo obr obs obt oc- oca ocb occ ocg ock oco ocr ocs oct oea oeb oec oee oeg oeo oer oes oet oga ogc oge ogg ogo ogs ogt oka okb okc oke okg okk oko okr oks oo- ooa oob ooc oog ook ooo oor oos oot or- ora orb orc ore org ork oro orr ors ort os- osa osb osc ose osg osk oso osr oss ost ot- ota otb otc ote otg otk oto otr ots ott ra- raa rab rac rae rag rak rao rar ras rat rba rbb rbc rbe rbg rbk rbo rbr rbs rbt rca rcb rcc rce rcg rco rcr rcs rct re- rea reb rec ree reg rek reo rer res ret rga rgb rgc rge rgg rgk rgo rgr rgs rgt rkb rkc rke rkg rkk rko rks rkt roa rob roc roe rog rok roo ror ros rot rra rrb rrc rrg rrk rrr rrs rrt rsa rsb rsc rse rsg rsk rso rsr rss rst rta rtb rtc rte rtg rtk rto rtr rts rtt saa sab sac sae sag sak sao sar sas sat sba sbb sbc sbe sbg sbk sbo sbr sbs sbt sca scb scc sce scg sck sco scr scs sct se- sea seb sec see seg sek seo ser ses set sga sgb sgc sge sgg sgk sgo sgr sgs sgt sk- ska skb skc ske skg skk sko skr sks skt soa sob soc soe sog sok soo sor sos sot sr- sra srb src sre srg srk sro srr srs srt ss- ssa ssb ssc sse ssg ssk sso ssr sss sst sta stb stc ste stg stk sto str sts stt taa tab tac tae tag tak tao tar tas tat tba tbb tbc tbe tbg tbk tbo tbr tbs tbt tca tcb tcc tce tcg tck tco tcr tcs tct te- tea teb tec tee teg tek teo ter tes tet tga tgb tgc tge tgg tgk tgo tgr tgs tgt tka tkb tkc tke tkg tkk tko tkr tks tkt to- toa tob toc toe tog tok too tor tos tot tra trb trc tre trg trk tro trr trs trt tsa tsb tsc tse tsg tsk tso tsr tss tst tta ttb ttc tte ttg ttk tto ttr tts ttt