a-a a-b a-c aaa aab aac aag aah aak aan aar ab- aba abb abc abg abh abk abn abr ac- aca acb acc acg ach ack acn acr ag- aga agb agc agg agh agk agn agr aha ahb ahc ahg ahh ahk ahn ahr aka akb akc akg akh akk akn akr an- ana anb anc ang anh ank ann anr ar- ara arb arc arg arh ark arn arr baa bab bac bag bah bak ban bar bba bbb bbc bbg bbh bbk bbn bbr bca bcb bcc bcg bch bck bcn bcr bga bgb bgc bgg bgh bgk bgn bgr bha bhb bhc bhg bhh bhk bhr bka bkb bkc bkg bkk bkn bkr bna bnb bnc bng bnk bnn bnr bra brb brg brh brk brn brr c-- caa cab cac cag cah cak can car cba cbb cbc cbg cbh cbk cbn cbr cca ccb ccc ccg cch cck ccn ccr cga cgb cgc cgg cgh cgn cgr ch- cha chb chc chg chh chk chn chr cka ckb ckc ckh cn- cna cnb cnc cng cnh cnn cnr cra crb crc crg crh crk crn crr gaa gab gac gag gah gak gan gar gba gbc gbg gbh gbk gbn gbr gca gcb gcc gcg gch gck gcn gcr gga ggb ggc ggg ggh ggn ggr gha ghb ghc ghg ghh ghn ghr gka gkb gkh gkn gna gnb gnc gnn gnr gra grb grc grg grh grk grn grr haa hab hac hag hah hak han har hba hbb hbc hbg hbh hbk hbn hbr hca hcb hcc hcg hch hck hcn hcr hga hgb hgc hgg hgh hgk hgn hgr hha hhb hhc hhg hhh hhk hhn hhr hka hkb hkg hkh hkk hkn hkr hna hnb hnc hng hnh hnk hnn hr- hra hrb hrc hrg hrh hrk hrn hrr ka- kaa kab kac kag kah kak kan kar kba kbb kbc kbh kbk kbn kbr kca kcb kcc kcg kch kck kcn kcr kga kgb kgc kgh kha khh khk khn khr kkb kkc kkh kkk kkn kkr kn- kna knc kng knk knn knr kra krc krg krk krn krr naa nab nac nag nah nak nan nar nba nbb nbc nbg nbk nbn nbr nca ncb ncc ncg nch nck ncn ncr nga ngb ngc ngg ngh ngk ngn nha nhb nhc nhg nhh nhk nhn nhr nka nkc nkk nkn nkr nna nnb nnc nng nnh nnk nnn nra nrb nrc nrg nrk nrn nrr ra- raa rab rac rag rah rak ran rar rba rbb rbc rbg rbh rbk rbn rbr rca rcb rcc rcg rch rcn rcr rga rgb rgc rgg rgh rgk rgn rgr rh- rha rhb rhc rhg rhh rhn rhr rkb rkc rkg rkk rna rnb rnc rng rnh rnn rnr rra rrb rrc rrg rrh rrk rrn rrr