a-a a-b a-c a-t aaa aab aac aak aan aao aat aau ab- aba abb abc abk abn abo abt abu ac- aca acb acc ack acn aco act acu aka akb akc akk akn ako aku an- ana anb anc ank ann ano ant anu aoa aob aoc aok aon aoo aot aou at- ata atb atc atn ato att atu au- aua aub auc auk aun auo aut b-u baa bab bac bak ban bao bat bau bba bbb bbc bbk bbn bbo bbt bbu bca bcb bcc bck bcn bco bct bcu bka bkb bkc bkk bkn bko bkt bna bnb bnc bnk bnn bno bnt bnu boa bob boc bok bon boo bot bou bta btb btc btk btn bto btt btu bua bub buc buk bun buo but buu c-- caa cab cac cak can cao cat cau cba cbb cbc cbk cbn cbo cbt cbu cca ccb ccc cck ccn cco cct ccu cka ckb ckc cko ckt cn- cna cnb cnc cnn cno cnt cnu co- coa cob coc cok con coo cot cou cta ctb ctc ctk ctn cto ctt ctu cua cub cuc cuk cun cuo cut cuu k-t ka- kaa kab kac kak kan kao kat kau kba kbb kbc kbk kbn kbo kbu kca kcb kcc kck kcn kct kcu kkb kkc kkk kkn kkt kku kn- kna knc knk knn kno knt knu koa kob koc kok kon koo kot kou kta ktb ktc ktk ktn kto ktt ktu kub kuc kuk kun kut kuu naa nab nac nak nan nao nat nau nba nbb nbc nbk nbn nbo nbt nbu nca ncb ncc nck ncn nco nct ncu nka nkc nkk nkn nko nkt nku nna nnb nnc nnk nnn nno nnt nnu no- noa nob noc nok non noo not nou nta ntb ntc ntk ntn nto ntt ntu nua nub nuc nuk nun nuo nut nuu oaa oab oac oak oan oao oat oau ob- oba obb obc obk obn obo obt obu oc- oca ocb occ ock ocn oco oct ocu oka okb okc okk oko oku on- ona onb onc onk onn ono ont onu oo- ooa oob ooc ook oon ooo oot ot- ota otb otc otk otn oto ott otu ou- oua ouc ouk oun ouo out taa tab tac tak tan tao tat tau tba tbb tbc tbk tbn tbo tbt tbu tca tcb tcc tck tcn tco tct tcu tka tkb tkc tkk tko tkt tna tnb tnc tnk tnn tno tnt to- toa tob toc tok ton too tot tou tta ttb ttc ttk ttn tto ttt ttu tua tub tuc tuk tun tuo tut tuu ua- uaa uab uac uak uan uao uat uau uba ubb ubc ubk ubn ubo ubt ubu uca ucb ucc uck ucn uco uct ucu uka ukb ukc ukk ukn uku un- una unb unc unk unn uno unt unu uoa uob uoc uok uon uoo uot uta utb utc utk utn uto utt utu uua uuc uun uut uuu