a-a a-b aaa aab aak aar aay ab- aba abb abk abr aby aka akb akk akr ar- ara arb ark arr ary ay- aya ayk ayr baa bab bak bar bay bba bbb bbk bbr bby bka bkb bkk bkr bra brb brk brr bry by- bya byk byr ka- kaa kab kak kar kay kba kbb kbk kbr kkb kkk kkr kky kra krk krr kry kya kyr ra- raa rab rak rar ray rba rbb rbk rbr rkb rkk rky rra rrb rrk rrr ry- rya ryk ryr ryy yaa yab yak yar yay ybr yby yka ykk yra yyb yyy