a-a a-b a-c aaa aab aac aae aah aak aan ab- aba abb abc abe abh abk abn ac- aca acb acc ace ach ack acn aea aeb aec aee aeh aek aen aha ahb ahc ahe ahh ahk ahn aka akb akc ake akh akk akn an- ana anb anc ane anh ank ann baa bab bac bae bah bak ban bba bbb bbc bbe bbh bbk bbn bca bcb bcc bce bch bck bcn be- bea beb bec bee beh bek ben bha bhb bhc bhe bhh bhk bka bkb bkc bke bkk bkn bna bnb bnc bne bnk bnn c-- caa cab cac cae cah cak can cba cbb cbc cbe cbh cbk cbn cca ccb ccc cce cch cck ccn ce- cea ceb cec cee ceh cek cen ch- cha chb chc che chh chk chn cka ckb ckc ckh cn- cna cnb cnc cne cnh cnn eaa eab eac eae eah eak ean eba ebb ebc ebe ebh ebk ebn ec- eca ecb ecc ece ech eck ecn eea eeb eec eee eek een eha ehb ehc ehe ehh ehn eka ekb ekc eke ekh en- ena enb enc ene enh enk enn haa hab hac hae hah hak han hba hbb hbc hbe hbh hbk hbn hca hcb hcc hce hch hck hcn he- hea heb hec hee heh hek hen hha hhb hhc hhe hhh hhk hhn hka hkb hkh hkk hkn hna hnb hnc hne hnh hnk hnn ka- kaa kab kac kae kah kak kan kba kbb kbc kbe kbh kbk kbn kca kcb kcc kce kch kck kcn ke- kea keb kec kee keh kek ken kha khe khh khk khn kkb kkc kke kkh kkk kkn kn- kna knc kne knk knn naa nab nac nae nah nak nan nba nbb nbc nbe nbk nbn nca ncb ncc nce nch nck ncn ne- nea neb nec nee neh nek nen nha nhb nhc nhe nhh nhk nhn nka nkc nke nkk nkn nna nnb nnc nne nnh nnk nnn