-er a-a a-b a-t aaa aab aae aaf aag aar aas aat ab- aba abb abe abf abg abr abs abt aea aeb aee aef aeg aer aes aet af- afa afb afe aff afg afr afs aft ag- aga agb age agf agg agr ags agt ar- ara arb are arf arg arr ars art as- asa asb ase asf asg asr ass ast at- ata atb ate atf atg atr ats att baa bab bae baf bag bar bas bat bba bbb bbe bbf bbg bbr bbs bbt be- bea beb bee bef beg ber bes bet bfa bfb bfe bff bfg bfr bfs bft bga bgb bge bgf bgg bgr bgs bgt bra brb bre brf brg brr brs brt bsa bsb bse bsf bsg bsr bss bst bta btb bte btf btg btr bts btt eaa eab eae eaf eag ear eas eat eba ebb ebe ebf ebg ebr ebs ebt eea eeb eee eef eeg eer ees eet ef- efa efb efe eff efg efr efs eft ega egb ege egf egg egr egs egt era erb ere erf erg err ers ert es- esa esb ese esf esg esr ess est eta etb ete etf etg etr ets ett faa fab fae faf fag far fas fat fba fbb fbe fbf fbg fbr fbs fbt fea feb fee fef feg fer fes fet ffa ffe fff ffg ffr ffs fft fga fgb fge fgf fgg fgr fgs fgt fra frb fre frf frg frr frs frt fsa fsb fse fsf fsg fsr fss fst fta ftb fte ftf ftg ftr fts ftt gaa gab gae gaf gag gar gas gat gba gbe gbf gbg gbr gbs gbt ge- gea geb gee gef geg ger ges get gfa gfb gfe gff gfr gfs gft gga ggb ggg ggr ggs ggt gra grb gre grf grg grr grs grt gsa gsb gse gsf gsg gsr gss gst gta gtb gte gtf gtg gtr gts gtt ra- raa rab rae raf rag rar ras rat rba rbb rbe rbf rbg rbr rbs rbt re- rea reb ree ref reg rer res ret rfa rfb rfe rff rfg rfr rfs rft rga rgb rge rgf rgg rgr rgs rgt rra rrb rrf rrg rrr rrs rrt rsa rsb rse rsf rsg rsr rss rst rta rtb rte rtf rtg rtr rts rtt saa sab sae saf sag sar sas sat sba sbb sbe sbf sbg sbr sbs sbt se- sea seb see sef seg ser ses set sfa sfb sfe sff sfg sfr sfs sft sga sgb sge sgf sgg sgr sgs sgt sr- sra srb sre srf srg srr srs srt ss- ssa ssb sse ssf ssg ssr sss sst sta stb ste stf stg str sts stt taa tab tae taf tag tar tas tat tba tbb tbe tbf tbg tbr tbs tbt te- tea teb tee tef teg ter tes tet tfa tfb tfe tff tfg tfr tfs tft tga tgb tge tgf tgg tgr tgs tgt tra trb tre trf trg trr trs trt tsa tsb tse tsf tsg tsr tss tst tta ttb tte ttf ttg ttr tts ttt