a-a a-b a-i aaa aab aag aah aai aao aax ab- aba abb abg abh abi abo abx ag- aga agb agg agh agi ago agx aha ahb ahg ahh ahi aho ahx ai- aia aib aig aih aii aio aix aoa aob aog aoh aoi aoo aox ax- axa axh axi axo axx baa bab bag bah bai bao bax bba bbb bbg bbh bbi bbo bbx bga bgb bgg bgh bgi bgo bgx bha bhb bhg bhh bhi bho bhx bi- bia bib big bih bii bio bix boa bob bog boh boi boo box bxb bxi bxo bxx gaa gab gag gah gai gao gba gbg gbh gbi gbo gbx gga ggb ggg ggh ggi ggo gha ghb ghg ghh ghi gho gia gib gig gih gii gio goa gob gog goh goi goo gox gxa h-i haa hab hag hah hai hao hax hba hbb hbg hbh hbi hbo hbx hga hgb hgg hgh hgi hgo hha hhb hhg hhh hhi hho hia hib hig hih hii hio hix hoa hob hog hoh hoi hoo hox ia- iaa iab iag iah iai iao iba ibb ibg ibh ibi ibo ibx iga igb igg igh igi igo iha ihb ihg ihh ihi iho iia iib iih iii iio iix io- ioa iob iog ioh ioi ioo ixi o-i oaa oab oag oah oai oao oax ob- oba obb obg obh obi obo obx oga ogg ogh ogi ogo ogx oha ohg ohh ohi oho oia oib oii oio oo- ooa oob oog ooh ooi ooo oox ox- oxa oxb oxi oxo oxx xaa xag xbx xgi xia xii xio xix xoa xog xoi xoo xox xxi xxo xxx