a-a a-b a-c a-t aaa aab aac aak aan aar aat aau ab- aba abb abc abk abn abr abt abu ac- aca acb acc ack acn acr act acu aka akb akc akk akn akr aku an- ana anb anc ank ann anr ant anu ar- ara arb arc ark arn arr art aru at- ata atb atc atn atr att atu au- aua aub auc auk aun aur aut b-u baa bab bac bak ban bar bat bau bba bbb bbc bbk bbn bbr bbt bbu bca bcb bcc bck bcn bcr bct bcu bka bkb bkc bkk bkn bkr bkt bna bnb bnc bnk bnn bnr bnt bnu bra brb brk brn brr brt bru bta btb btc btk btn btr btt btu bua bub buc buk bun bur but buu c-- caa cab cac cak can car cat cau cba cbb cbc cbk cbn cbr cbt cbu cca ccb ccc cck ccn ccr cct ccu cka ckb ckc ckt cn- cna cnb cnc cnn cnr cnt cnu cra crb crc crk crn crr crt cru cta ctb ctc ctk ctn ctr ctt ctu cua cub cuc cuk cun cur cut cuu k-t ka- kaa kab kac kak kan kar kat kau kba kbb kbc kbk kbn kbr kbu kca kcb kcc kck kcn kcr kct kcu kkb kkc kkk kkn kkr kkt kku kn- kna knc knk knn knr knt knu kra krc krk krn krr krt kru kta ktb ktc ktk ktn ktr ktt ktu kub kuc kuk kun kur kut kuu naa nab nac nak nan nar nat nau nba nbb nbc nbk nbn nbr nbt nbu nca ncb ncc nck ncn ncr nct ncu nka nkc nkk nkn nkr nkt nku nna nnb nnc nnk nnn nnt nnu nra nrb nrc nrk nrn nrr nrt nru nta ntb ntc ntk ntn ntr ntt ntu nua nub nuc nuk nun nur nut nuu ra- raa rab rac rak ran rar rat rau rba rbb rbc rbk rbn rbr rbt rbu rca rcb rcc rcn rcr rct rcu rkb rkc rkk rkt rku rna rnb rnc rnn rnr rnt rnu rra rrb rrc rrk rrn rrr rrt rru rta rtb rtc rtk rtn rtr rtt rtu rua rub ruc ruk run rur rut ruu taa tab tac tak tan tar tat tau tba tbb tbc tbk tbn tbr tbt tbu tca tcb tcc tck tcn tcr tct tcu tka tkb tkc tkk tkr tkt tna tnb tnc tnk tnn tnr tnt tra trb trc trk trn trr trt tru tta ttb ttc ttk ttn ttr ttt ttu tua tub tuc tuk tun tur tut tuu ua- uaa uab uac uak uan uar uat uau uba ubb ubc ubk ubn ubr ubt ubu uca ucb ucc uck ucn ucr uct ucu uka ukb ukc ukk ukn ukr uku un- una unb unc unk unn unr unt unu ur- ura urb urc urk urn urr urt uru uta utb utc utk utn utr utt utu uua uuc uun uur uut uuu