a-a a-b a-t aaa aab aan aao aar aat aax ab- aba abb abn abo abr abt abx an- ana anb ann ano anr ant anx aoa aob aon aoo aor aot aox ar- ara arb arn aro arr art arx at- ata atb atn ato atr att atx ax- axa axn axo axr axt axx baa bab ban bao bar bat bax bba bbb bbn bbo bbr bbt bbx bna bnb bnn bno bnr bnt bnx boa bob bon boo bor bot box bra brb brn bro brr brt brx bta btb btn bto btr btt btx bxb bxn bxo bxx naa nab nan nao nar nat nax nba nbb nbn nbo nbr nbt nbx nna nnb nnn nno nnt no- noa nob non noo nor not nox nra nrb nrn nro nrr nrt nrx nta ntb ntn nto ntr ntt ntx nxt oaa oab oan oao oar oat oax ob- oba obb obn obo obr obt obx on- ona onb onn ono onr ont onx oo- ooa oob oon ooo oor oot oox or- ora orb orn oro orr ort orx ot- ota otb otn oto otr ott ox- oxa oxb oxn oxo oxt oxx ra- raa rab ran rao rar rat rax rba rbb rbn rbo rbr rbt rbx rna rnb rnn rno rnr rnt roa rob ron roo ror rot rox rra rrb rrn rrr rrt rta rtb rtn rto rtr rtt rtx rxr t-x taa tab tan tao tar tat tax tba tbb tbn tbo tbr tbt tna tnb tnn tno tnr tnt tnx to- toa tob ton too tor tot tox tra trb trn tro trr trt trx tta ttb ttn tto ttr ttt ttx txn txt xaa xan xar xat xbr xbx xna xno xoa xon xoo xor xot xox xrt xrx xtr xtx xxo xxx