a-a a-b a-i a-t aaa aab aag aai aao aar aas aat ab- aba abb abg abi abo abr abs abt ag- aga agb agg agi ago agr ags agt ai- aia aib aig aii aio air ais ait aoa aob aog aoi aoo aor aos aot ar- ara arb arg ari aro arr ars art as- asa asb asg asi aso asr ass ast at- ata atb atg ati ato atr ats att baa bab bag bai bao bar bas bat bba bbb bbg bbi bbo bbr bbs bbt bga bgb bgg bgi bgo bgr bgs bgt bi- bia bib big bii bio bir bis bit boa bob bog boi boo bor bos bot bra brb brg bri bro brr brs brt bsa bsb bsg bsi bso bsr bss bst bta btb btg bti bto btr bts btt gaa gab gag gai gao gar gas gat gba gbg gbi gbo gbr gbs gbt gga ggb ggg ggi ggo ggr ggs ggt gia gib gig gii gio gir gis git goa gob gog goi goo gor gos got gra grb grg gri gro grr grs grt gsa gsb gsg gsi gso gsr gss gst gta gtb gtg gti gto gtr gts gtt ia- iaa iab iag iai iao iar ias iat iba ibb ibg ibi ibo ibr ibs ibt iga igb igg igi igo igr igs igt iia iib iii iio iir iis iit io- ioa iob iog ioi ioo ior ios iot ir- ira irb irg iri iro irr irs irt is- isa isb isg isi iso isr iss ist ita itb itg iti ito its itt o-i oaa oab oag oai oao oar oas oat ob- oba obb obg obi obo obr obs obt oga ogg ogi ogo ogs ogt oia oib oii oio oir ois oit oo- ooa oob oog ooi ooo oor oos oot or- ora orb org ori oro orr ors ort os- osa osb osg osi oso osr oss ost ot- ota otb otg oti oto otr ots ott ra- raa rab rag rai rao rar ras rat rba rbb rbg rbi rbo rbr rbs rbt rga rgb rgg rgi rgo rgr rgs rgt ria rib rig rii rio rir ris rit roa rob rog roi roo ror ros rot rra rrb rrg rri rrr rrs rrt rsa rsb rsg rsi rso rsr rss rst rta rtb rtg rti rto rtr rts rtt saa sab sag sai sao sar sas sat sba sbb sbg sbi sbo sbr sbs sbt sga sgb sgg sgi sgo sgr sgs sgt sia sib sig sii sio sir sis sit soa sob sog soi soo sor sos sot sr- sra srb srg sri sro srr srs srt ss- ssa ssb ssg ssi sso ssr sss sst sta stb stg sti sto str sts stt taa tab tag tai tao tar tas tat tba tbb tbg tbi tbo tbr tbs tbt tga tgb tgg tgi tgo tgr tgs tgt tia tib tig tii tio tir tis tit to- toa tob tog toi too tor tos tot tra trb trg tri tro trr trs trt tsa tsb tsg tsi tso tsr tss tst tta ttb ttg tti tto ttr tts ttt