a-a a-b a-t aaa aab aam aan aar aat ab- aba abb abm abn abr abt ama amb amm amn amr amt an- ana anb anm ann anr ant ar- ara arb arm arn arr art at- ata atb atm atn atr att baa bab bam ban bar bat bba bbb bbm bbn bbr bbt bma bmb bmm bmn bmr bmt bna bnb bnn bnr bnt bra brb brm brn brr brt bta btb btm btn btr btt m-r maa mab mam man mar mat mba mbb mbm mbr mbt mma mmb mmm mmn mmr mmt mna mnb mnm mnn mnr mnt mra mrb mrm mrn mrr mrt mta mtb mtm mtn mtr mtt naa nab nam nan nar nat nba nbb nbm nbn nbr nbt nma nmb nmm nmn nmr nmt nna nnb nnm nnn nnt nra nrb nrm nrn nrr nrt nta ntb ntm ntn ntr ntt ra- raa rab ram ran rar rat rba rbb rbm rbn rbr rbt rma rmb rmm rmn rmr rmt rna rnb rnm rnn rnr rnt rra rrb rrm rrn rrr rrt rta rtb rtm rtn rtr rtt taa tab tam tan tar tat tba tbb tbm tbn tbr tbt tma tmb tmm tmn tmr tmt tna tnb tnm tnn tnr tnt tra trb trm trn trr trt tta ttb ttm ttn ttr ttt