a-a a-b a-c aaa aab aac aam aao aar aau ab- aba abb abc abm abo abr abu ac- aca acb acc acm aco acr acu ama amb amc amm amo amr amu aoa aob aoc aom aoo aor aou ar- ara arb arc arm aro arr aru au- aua aub auc aum auo aur b-u baa bab bac bam bao bar bau bba bbb bbc bbm bbo bbr bbu bca bcb bcc bcm bco bcr bcu bma bmb bmc bmm bmo bmr bmu boa bob boc bom boo bor bou bra brb brm bro brr bru bua bub buc bum buo bur buu c-- caa cab cac cam cao car cau cba cbb cbc cbm cbo cbr cbu cca ccb ccc ccm cco ccr ccu cma cmb cmc cmm cmo cmr cmu co- coa cob coc com coo cor cou cra crb crc crm cro crr cru cua cub cuc cum cuo cur cuu m-o m-r maa mab mac mam mao mar mau mba mbb mbc mbm mbo mbr mbu mc- mca mcb mcc mcm mco mcr mcu mma mmb mmc mmm mmo mmr mmu moa mob moc mom moo mor mou mra mrb mrc mrm mro mrr mru mua mub muc mum mur muu oaa oab oac oam oao oar oau ob- oba obb obc obm obo obr obu oc- oca ocb occ ocm oco ocr ocu om- oma omb omc omm omo omr omu oo- ooa oob ooc oom ooo oor or- ora orb orc orm oro orr oru ou- oua ouc oum ouo our ra- raa rab rac ram rao rar rau rba rbb rbc rbm rbo rbr rbu rca rcb rcc rcm rco rcr rcu rma rmb rmc rmm rmo rmr roa rob roc rom roo ror rou rra rrb rrc rrm rrr rru rua rub ruc rum ruo rur ruu ua- uaa uab uac uam uao uar uau uba ubb ubc ubo ubr ubu uca ucb ucc ucm uco ucr ucu um- uma umb umc umm umo umr umu uoa uob uoc uom uoo uor ur- ura urb urc urm uro urr uru uua uuc uum uur uuu