a-a a-b a-c aaa aab aac aae aag aah aak aan ab- aba abb abc abe abg abh abk abn ac- aca acb acc ace acg ach ack acn aea aeb aec aee aeg aeh aek aen ag- aga agb agc age agg agh agk agn aha ahb ahc ahe ahg ahh ahk ahn aka akb akc ake akg akh akk akn an- ana anb anc ane ang anh ank ann baa bab bac bae bag bah bak ban bba bbb bbc bbe bbg bbh bbk bbn bca bcb bcc bce bcg bch bck bcn be- bea beb bec bee beg beh bek ben bga bgb bgc bge bgg bgh bgk bgn bha bhb bhc bhe bhg bhh bhk bka bkb bkc bke bkg bkk bkn bna bnb bnc bne bng bnk bnn c-- caa cab cac cae cag cah cak can cba cbb cbc cbe cbg cbh cbk cbn cca ccb ccc cce ccg cch cck ccn ce- cea ceb cec cee ceg ceh cek cen cga cgb cgc cge cgg cgh cgn ch- cha chb chc che chg chh chk chn cka ckb ckc ckh cn- cna cnb cnc cne cng cnh cnn eaa eab eac eae eag eah eak ean eba ebb ebc ebe ebg ebh ebk ebn ec- eca ecb ecc ece ecg ech eck ecn eea eeb eec eee eeg eek een ega egb egc ege egg egh egn eha ehb ehc ehe ehg ehh ehn eka ekb ekc eke ekg ekh en- ena enb enc ene eng enh enk enn gaa gab gac gae gag gah gak gan gba gbc gbe gbg gbh gbk gbn gca gcb gcc gce gcg gch gck gcn ge- gea geb gec gee geg geh gek gen gga ggb ggc ggg ggh ggn gha ghb ghc ghe ghg ghh ghn gka gkb gkh gkn gna gnb gnc gne gnn haa hab hac hae hag hah hak han hba hbb hbc hbe hbg hbh hbk hbn hca hcb hcc hce hcg hch hck hcn he- hea heb hec hee heg heh hek hen hga hgb hgc hge hgg hgh hgk hgn hha hhb hhc hhe hhg hhh hhk hhn hka hkb hkg hkh hkk hkn hna hnb hnc hne hng hnh hnk hnn ka- kaa kab kac kae kag kah kak kan kba kbb kbc kbe kbh kbk kbn kca kcb kcc kce kcg kch kck kcn ke- kea keb kec kee keg keh kek ken kga kgb kgc kgh kha khe khh khk khn kkb kkc kke kkh kkk kkn kn- kna knc kne kng knk knn naa nab nac nae nag nah nak nan nba nbb nbc nbe nbg nbk nbn nca ncb ncc nce ncg nch nck ncn ne- nea neb nec nee neg neh nek nen nga ngb ngc nge ngg ngh ngk ngn nha nhb nhc nhe nhg nhh nhk nhn nka nkc nke nkk nkn nna nnb nnc nne nng nnh nnk nnn