a-a a-b a-t aaa aab aak aan aao aar aat ab- aba abb abk abn abo abr abt aka akb akk akn ako akr an- ana anb ank ann ano anr ant aoa aob aok aon aoo aor aot ar- ara arb ark arn aro arr art at- ata atb atn ato atr att baa bab bak ban bao bar bat bba bbb bbk bbn bbo bbr bbt bka bkb bkk bkn bko bkr bkt bna bnb bnk bnn bno bnr bnt boa bob bok bon boo bor bot bra brb brk brn bro brr brt bta btb btk btn bto btr btt k-t ka- kaa kab kak kan kao kar kat kba kbb kbk kbn kbo kbr kkb kkk kkn kkr kkt kn- kna knk knn kno knr knt koa kob kok kon koo kor kot kra krk krn kro krr krt kta ktb ktk ktn kto ktr ktt naa nab nak nan nao nar nat nba nbb nbk nbn nbo nbr nbt nka nkk nkn nko nkr nkt nna nnb nnk nnn nno nnt no- noa nob nok non noo nor not nra nrb nrk nrn nro nrr nrt nta ntb ntk ntn nto ntr ntt oaa oab oak oan oao oar oat ob- oba obb obk obn obo obr obt oka okb okk oko okr on- ona onb onk onn ono onr ont oo- ooa oob ook oon ooo oor oot or- ora orb ork orn oro orr ort ot- ota otb otk otn oto otr ott ra- raa rab rak ran rao rar rat rba rbb rbk rbn rbo rbr rbt rkb rkk rko rkt rna rnb rnn rno rnr rnt roa rob rok ron roo ror rot rra rrb rrk rrn rrr rrt rta rtb rtk rtn rto rtr rtt taa tab tak tan tao tar tat tba tbb tbk tbn tbo tbr tbt tka tkb tkk tko tkr tkt tna tnb tnk tnn tno tnr tnt to- toa tob tok ton too tor tot tra trb trk trn tro trr trt tta ttb ttk ttn tto ttr ttt