a-a a-b a-t aaa aab aan aao aap aar aat ab- aba abb abn abo abp abr abt an- ana anb ann ano anp anr ant aoa aob aon aoo aop aor aot ap- apa apb apn apo app apr apt ar- ara arb arn aro arp arr art at- ata atb atn ato atp atr att b-p baa bab ban bao bap bar bat bba bbb bbn bbo bbp bbr bbt bna bnb bnn bno bnp bnr bnt boa bob bon boo bop bor bot bpa bpb bpn bpo bpp bpr bpt bra brb brn bro brp brr brt bta btb btn bto btp btr btt naa nab nan nao nap nar nat nba nbb nbn nbo nbp nbr nbt nna nnb nnn nno nnp nnt no- noa nob non noo nop nor not npa npb npn npo npp npr npt nra nrb nrn nro nrp nrr nrt nta ntb ntn nto ntp ntr ntt oaa oab oan oao oap oar oat ob- oba obb obn obo obp obr obt on- ona onb onn ono onp onr ont oo- ooa oob oon ooo oop oor oot op- opa opb opn opo opp opr opt or- ora orb orn oro orp orr ort ot- ota otb otn oto otp otr ott p-p paa pab pan pao pap par pat pba pbb pbn pbo pbp pbr pbt pn- pna pnb pnn pno pnp pnr pnt poa pob pon poo pop por pot ppa ppb ppn ppo ppp ppr ppt pra prb prn pro prp prr prt pt- pta ptb ptn pto ptp ptr ptt ra- raa rab ran rao rap rar rat rba rbb rbn rbo rbp rbr rbt rna rnb rnn rno rnp rnr rnt roa rob ron roo rop ror rot rpa rpb rpn rpo rpp rpr rpt rra rrb rrn rrp rrr rrt rta rtb rtn rto rtp rtr rtt taa tab tan tao tap tar tat tba tbb tbn tbo tbp tbr tbt tna tnb tnn tno tnp tnr tnt to- toa tob ton too top tor tot tpa tpb tpn tpo tpp tpr tpt tra trb trn tro trp trr trt tta ttb ttn tto ttp ttr ttt