a-a a-b aaa aab aak aan aay ab- aba abb abk abn aby aka akb akk akn an- ana anb ank ann any ay- aya ayk ayn baa bab bak ban bay bba bbb bbk bbn bby bka bkb bkk bkn bna bnb bnk bnn by- bya byk byn ka- kaa kab kak kan kay kba kbb kbk kbn kkb kkk kkn kky kn- kna knk knn kya kyn naa nab nak nan nay nba nbb nbk nbn nka nkk nkn nky nna nnb nnk nnn nya nyk nyn nyy yaa yab yak yan yay yby yka ykk ykn yna ynk ynn yny yyb yyy