a-a a-b aaa aab aan aar aay ab- aba abb abn abr aby an- ana anb ann anr any ar- ara arb arn arr ary ay- aya ayn ayr baa bab ban bar bay bba bbb bbn bbr bby bna bnb bnn bnr bra brb brn brr bry by- bya byn byr naa nab nan nar nay nba nbb nbn nbr nna nnb nnn nra nrb nrn nrr nry nya nyn nyy ra- raa rab ran rar ray rba rbb rbn rbr rna rnb rnn rnr rny rra rrb rrn rrr ry- rya ryn ryr ryy yaa yab yan yar yay ybr yby yna ynn yny yra yrn yyb yyy