a-a a-b a-c aaa aab aac aam aao aau ab- aba abb abc abm abo abu ac- aca acb acc acm aco acu ama amb amc amm amo amu aoa aob aoc aom aoo aou au- aua aub auc aum auo b-u baa bab bac bam bao bau bba bbb bbc bbm bbo bbu bca bcb bcc bcm bco bcu bma bmb bmc bmm bmo bmu boa bob boc bom boo bou bua bub buc bum buo buu c-- caa cab cac cam cao cau cba cbb cbc cbm cbo cbu cca ccb ccc ccm cco ccu cma cmb cmc cmm cmo cmu co- coa cob coc com coo cou cua cub cuc cum cuo cuu m-o maa mab mac mam mao mau mba mbb mbc mbm mbo mbu mc- mca mcb mcc mcm mco mcu mma mmb mmc mmm mmo mmu moa mob moc mom moo mou mua mub muc mum muu oaa oab oac oam oao oau ob- oba obb obc obm obo obu oc- oca ocb occ ocm oco ocu om- oma omb omc omm omo omu oo- ooa oob ooc oom ooo ou- oua ouc oum ouo ua- uaa uab uac uam uao uau uba ubb ubc ubo ubu uca ucb ucc ucm uco ucu um- uma umb umc umm umo umu uoa uob uoc uom uoo uua uuc uum uuu