a-a a-b a-c aaa aab aac aae aag aah aan ab- aba abb abc abe abg abh abn ac- aca acb acc ace acg ach acn aea aeb aec aee aeg aeh aen ag- aga agb agc age agg agh agn aha ahb ahc ahe ahg ahh ahn an- ana anb anc ane ang anh ann baa bab bac bae bag bah ban bba bbb bbc bbe bbg bbh bbn bca bcb bcc bce bcg bch bcn be- bea beb bec bee beg beh ben bga bgb bgc bge bgg bgh bgn bha bhb bhc bhe bhg bhh bna bnb bnc bne bng bnn c-- caa cab cac cae cag cah can cba cbb cbc cbe cbg cbh cbn cca ccb ccc cce ccg cch ccn ce- cea ceb cec cee ceg ceh cen cga cgb cgc cge cgg cgh cgn ch- cha chb chc che chg chh chn cn- cna cnb cnc cne cng cnh cnn eaa eab eac eae eag eah ean eba ebb ebc ebe ebg ebh ebn ec- eca ecb ecc ece ecg ech ecn eea eeb eec eee eeg een ega egb egc ege egg egh egn eha ehb ehc ehe ehg ehh ehn en- ena enb enc ene eng enh enn gaa gab gac gae gag gah gan gba gbc gbe gbg gbh gbn gca gcb gcc gce gcg gch gcn ge- gea geb gec gee geg geh gen gga ggb ggc ggg ggh ggn gha ghb ghc ghe ghg ghh ghn gna gnb gnc gne gnn haa hab hac hae hag hah han hba hbb hbc hbe hbg hbh hbn hca hcb hcc hce hcg hch hcn he- hea heb hec hee heg heh hen hga hgb hgc hge hgg hgh hgn hha hhb hhc hhe hhg hhh hhn hna hnb hnc hne hng hnh hnn naa nab nac nae nag nah nan nba nbb nbc nbe nbg nbn nca ncb ncc nce ncg nch ncn ne- nea neb nec nee neg neh nen nga ngb ngc nge ngg ngh ngn nha nhb nhc nhe nhg nhh nhn nna nnb nnc nne nng nnh nnn