a-a a-b a-c aaa aab aac aak aam aar aau ab- aba abb abc abk abm abr abu ac- aca acb acc ack acm acr acu aka akb akc akk akm akr aku ama amb amc amk amm amr amu ar- ara arb arc ark arm arr aru au- aua aub auc auk aum aur b-u baa bab bac bak bam bar bau bba bbb bbc bbk bbm bbr bbu bca bcb bcc bck bcm bcr bcu bka bkb bkc bkk bkm bkr bma bmb bmc bmk bmm bmr bmu bra brb brk brm brr bru bua bub buc buk bum bur buu c-- caa cab cac cak cam car cau cba cbb cbc cbk cbm cbr cbu cca ccb ccc cck ccm ccr ccu cka ckb ckc ckm cma cmb cmc cmk cmm cmr cmu cra crb crc crk crm crr cru cua cub cuc cuk cum cur cuu ka- kaa kab kac kak kam kar kau kba kbb kbc kbk kbm kbr kbu kca kcb kcc kck kcm kcr kcu kkb kkc kkk kkm kkr kku kma kmb kmc kmk kmm kmu kra krc krk krr kru kub kuc kuk kum kur kuu m-r maa mab mac mak mam mar mau mba mbb mbc mbk mbm mbr mbu mc- mca mcb mcc mck mcm mcr mcu mka mkb mkc mkk mkm mkr mku mma mmb mmc mmk mmm mmr mmu mra mrb mrc mrk mrm mrr mru mua mub muc muk mum mur muu ra- raa rab rac rak ram rar rau rba rbb rbc rbk rbm rbr rbu rca rcb rcc rcm rcr rcu rkb rkc rkk rkm rku rma rmb rmc rmm rmr rra rrb rrc rrk rrm rrr rru rua rub ruc ruk rum rur ruu ua- uaa uab uac uak uam uar uau uba ubb ubc ubk ubr ubu uca ucb ucc uck ucm ucr ucu uka ukb ukc ukk ukr uku um- uma umb umc umm umr umu ur- ura urb urc urk urm urr uru uua uuc uum uur uuu