a-a a-b a-t aaa aab aan aar aat aay ab- aba abb abn abr abt aby an- ana anb ann anr ant any ar- ara arb arn arr art ary at- ata atb atn atr att ay- aya ayn ayr ayt baa bab ban bar bat bay bba bbb bbn bbr bbt bby bna bnb bnn bnr bnt bra brb brn brr brt bry bta btb btn btr btt bty by- bya byn byr byt naa nab nan nar nat nay nba nbb nbn nbr nbt nna nnb nnn nnt nra nrb nrn nrr nrt nry nta ntb ntn ntr ntt nya nyn nyt nyy ra- raa rab ran rar rat ray rba rbb rbn rbr rbt rna rnb rnn rnr rnt rny rra rrb rrn rrr rrt rta rtb rtn rtr rtt rty ry- rya ryn ryr ryy taa tab tan tar tat tay tba tbb tbn tbr tbt tna tnb tnn tnr tnt tra trb trn trr trt try tta ttb ttn ttr ttt tty tya tyn tyr tyt yaa yab yan yar yat yay ybr yby yna ynn yny yra yrn yrt yta ytn ytr ytt yyb yyt yyy