a-a a-b a-t aaa aab aak aan aar aat aau ab- aba abb abk abn abr abt abu aka akb akk akn akr aku an- ana anb ank ann anr ant anu ar- ara arb ark arn arr art aru at- ata atb atn atr att atu au- aua aub auk aun aur aut b-u baa bab bak ban bar bat bau bba bbb bbk bbn bbr bbt bbu bka bkb bkk bkn bkr bkt bna bnb bnk bnn bnr bnt bnu bra brb brk brn brr brt bru bta btb btk btn btr btt btu bua bub buk bun bur but buu k-t ka- kaa kab kak kan kar kat kau kba kbb kbk kbn kbr kbu kkb kkk kkn kkr kkt kku kn- kna knk knn knr knt knu kra krk krn krr krt kru kta ktb ktk ktn ktr ktt ktu kub kuk kun kur kut kuu naa nab nak nan nar nat nau nba nbb nbk nbn nbr nbt nbu nka nkk nkn nkr nkt nku nna nnb nnk nnn nnt nnu nra nrb nrk nrn nrr nrt nru nta ntb ntk ntn ntr ntt ntu nua nub nuk nun nur nut nuu ra- raa rab rak ran rar rat rau rba rbb rbk rbn rbr rbt rbu rkb rkk rkt rku rna rnb rnn rnr rnt rnu rra rrb rrk rrn rrr rrt rru rta rtb rtk rtn rtr rtt rtu rua rub ruk run rur rut ruu taa tab tak tan tar tat tau tba tbb tbk tbn tbr tbt tbu tka tkb tkk tkr tkt tna tnb tnk tnn tnr tnt tra trb trk trn trr trt tru tta ttb ttk ttn ttr ttt ttu tua tub tuk tun tur tut tuu ua- uaa uab uak uan uar uat uau uba ubb ubk ubn ubr ubt ubu uka ukb ukk ukn ukr uku un- una unb unk unn unr unt unu ur- ura urb urk urn urr urt uru uta utb utk utn utr utt utu uua uun uur uut uuu