a-a a-b a-c aaa aab aac aah aam aao ab- aba abb abc abh abm abo ac- aca acb acc ach acm aco aha ahb ahc ahh ahm aho ama amb amc amh amm amo aoa aob aoc aoh aom aoo baa bab bac bah bam bao bba bbb bbc bbh bbm bbo bca bcb bcc bch bcm bco bha bhb bhc bhh bhm bho bma bmb bmc bmh bmm bmo boa bob boc boh bom boo c-- caa cab cac cah cam cao cba cbb cbc cbh cbm cbo cca ccb ccc cch ccm cco ch- cha chb chc chh chm cho cma cmb cmc cmh cmm cmo co- coa cob coc coh com coo haa hab hac hah ham hao hba hbb hbc hbh hbm hbo hca hcb hcc hch hcm hco hha hhb hhc hhh hhm hho hma hmb hmc hmh hmm hmo hoa hob hoc hoh hom hoo m-o maa mab mac mah mam mao mba mbb mbc mbh mbm mbo mc- mca mcb mcc mch mcm mco mha mhc mhh mhm mho mma mmb mmc mmh mmm mmo moa mob moc moh mom moo oaa oab oac oah oam oao ob- oba obb obc obh obm obo oc- oca ocb occ och ocm oco oha ohc ohh ohm oho om- oma omb omc omh omm omo oo- ooa oob ooc ooh oom ooo