-er -ic a-a a-b a-c a-i a-t aaa aab aac aae aag aai aak aar aas aat ab- aba abb abc abe abg abi abk abr abs abt ac- aca acb acc ace acg aci ack acr acs act aea aeb aec aee aeg aei aek aer aes aet ag- aga agb agc age agg agi agk agr ags agt ai- aia aib aic aie aig aii aik air ais ait aka akb akc ake akg aki akk akr aks ar- ara arb arc are arg ari ark arr ars art as- asa asb asc ase asg asi ask asr ass ast at- ata atb atc ate atg ati atr ats att baa bab bac bae bag bai bak bar bas bat bba bbb bbc bbe bbg bbi bbk bbr bbs bbt bca bcb bcc bce bcg bci bck bcr bcs bct be- bea beb bec bee beg bei bek ber bes bet bga bgb bgc bge bgg bgi bgk bgr bgs bgt bi- bia bib bic bie big bii bik bir bis bit bka bkb bkc bke bkg bkk bkr bks bkt bra brb bre brg bri brk brr brs brt bsa bsb bsc bse bsg bsi bsk bsr bss bst bta btb btc bte btg bti btk btr bts btt c-- caa cab cac cae cag cai cak car cas cat cba cbb cbc cbe cbg cbi cbk cbr cbs cbt cca ccb ccc cce ccg cci cck ccr ccs cct ce- cea ceb cec cee ceg cei cek cer ces cet cga cgb cgc cge cgg cgi cgr cgs cgt ci- cia cib cic cie cig cii cik cir cis cit cka ckb ckc cki cks ckt cra crb crc cre crg cri crk crr crs crt csa csb csc cse csg csi csk csr css cst cta ctb ctc cte ctg cti ctk ctr cts ctt eaa eab eac eae eag eai eak ear eas eat eba ebb ebc ebe ebg ebi ebk ebr ebs ebt ec- eca ecb ecc ece ecg eci eck ecr ecs ect eea eeb eec eee eeg eek eer ees eet ega egb egc ege egg egi egr egs egt eia eib eic eie eig eii eik eir eis eit eka ekb ekc eke ekg eki ekr eks ekt era erb erc ere erg eri erk err ers ert es- esa esb esc ese esg esi esk esr ess est eta etb etc ete etg eti etk etr ets ett gaa gab gac gae gag gai gak gar gas gat gba gbc gbe gbg gbi gbk gbr gbs gbt gca gcb gcc gce gcg gci gck gcr gcs gct ge- gea geb gec gee geg gei gek ger ges get gga ggb ggc ggg ggi ggr ggs ggt gia gib gic gie gig gii gik gir gis git gka gkb gks gkt gra grb grc gre grg gri grk grr grs grt gsa gsb gsc gse gsg gsi gsk gsr gss gst gta gtb gtc gte gtg gti gtk gtr gts gtt ia- iaa iab iac iae iag iai iar ias iat iba ibb ibc ibe ibg ibi ibk ibr ibs ibt ica icb icc ice icg ici ick icr ics ict ie- iea iec iee ieg iei iek ier ies iet iga igb igc ige igg igi igk igr igs igt iia iib iic iie iii iir iis iit ika ikb ikc ike iki ikk ikr iks ikt ir- ira irb irc ire irg iri irk irr irs irt is- isa isb isc ise isg isi isk isr iss ist ita itb itc ite itg iti itk its itt k-t ka- kaa kab kac kae kag kai kak kar kas kat kba kbb kbc kbe kbi kbk kbr kbs kca kcb kcc kce kcg kci kck kcr kcs kct ke- kea keb kec kee keg kei kek ker kes ket kga kgb kgc kgi kgs kia kib kic kie kig kii kik kir kis kit kkb kkc kke kki kkk kkr kks kkt kra krc krg kri krk krr krs krt ksa ksb ksc kse ksg ksi ksk ksr kss kst kta ktb ktc kte ktg ktk ktr kts ktt ra- raa rab rac rae rag rai rak rar ras rat rba rbb rbc rbe rbg rbi rbk rbr rbs rbt rca rcb rcc rce rcg rci rcr rcs rct re- rea reb rec ree reg rei rek rer res ret rga rgb rgc rge rgg rgi rgk rgr rgs rgt ria rib ric rie rig rii rik rir ris rit rkb rkc rke rkg rkk rks rkt rra rrb rrc rrg rri rrk rrr rrs rrt rsa rsb rsc rse rsg rsi rsk rsr rss rst rta rtb rtc rte rtg rti rtk rtr rts rtt saa sab sac sae sag sai sak sar sas sat sba sbb sbc sbe sbg sbi sbk sbr sbs sbt sca scb scc sce scg sci sck scr scs sct se- sea seb sec see seg sei sek ser ses set sga sgb sgc sge sgg sgi sgk sgr sgs sgt sia sib sic sie sig sii sik sir sis sit sk- ska skb skc ske skg ski skk skr sks skt sr- sra srb src sre srg sri srk srr srs srt ss- ssa ssb ssc sse ssg ssi ssk ssr sss sst sta stb stc ste stg sti stk str sts stt taa tab tac tae tag tai tak tar tas tat tba tbb tbc tbe tbg tbi tbk tbr tbs tbt tca tcb tcc tce tcg tci tck tcr tcs tct te- tea teb tec tee teg tei tek ter tes tet tga tgb tgc tge tgg tgi tgk tgr tgs tgt tia tib tic tie tig tii tik tir tis tit tka tkb tkc tke tkg tkk tkr tks tkt tra trb trc tre trg tri trk trr trs trt tsa tsb tsc tse tsg tsi tsk tsr tss tst tta ttb ttc tte ttg tti ttk ttr tts ttt