a-a a-b aaa aab aae aah aak aan ab- aba abb abe abh abk abn aea aeb aee aeh aek aen aha ahb ahe ahh ahk ahn aka akb ake akh akk akn an- ana anb ane anh ank ann baa bab bae bah bak ban bba bbb bbe bbh bbk bbn be- bea beb bee beh bek ben bha bhb bhe bhh bhk bka bkb bke bkk bkn bna bnb bne bnk bnn eaa eab eae eah eak ean eba ebb ebe ebh ebk ebn eea eeb eee eek een eha ehb ehe ehh ehn eka ekb eke ekh en- ena enb ene enh enk enn haa hab hae hah hak han hba hbb hbe hbh hbk hbn he- hea heb hee heh hek hen hha hhb hhe hhh hhk hhn hka hkb hkh hkk hkn hna hnb hne hnh hnk hnn ka- kaa kab kae kah kak kan kba kbb kbe kbh kbk kbn ke- kea keb kee keh kek ken kha khe khh khk khn kkb kke kkh kkk kkn kn- kna kne knk knn naa nab nae nah nak nan nba nbb nbe nbk nbn ne- nea neb nee neh nek nen nha nhb nhe nhh nhk nhn nka nke nkk nkn nna nnb nne nnh nnk nnn