a-a a-b a-i aaa aab aae aag aai aao ab- aba abb abe abg abi abo aea aeb aee aeg aei aeo ag- aga agb age agg agi ago ai- aia aib aie aig aii aio aoa aob aoe aog aoi aoo baa bab bae bag bai bao bba bbb bbe bbg bbi bbo be- bea beb bee beg bei beo bga bgb bge bgg bgi bgo bi- bia bib bie big bii bio boa bob boe bog boi boo eaa eab eae eag eai eao eba ebb ebe ebg ebi ebo eea eeb eee eeg eeo ega egb ege egg egi ego eia eib eie eig eii eio eo- eoa eob eoe eog eoi eoo gaa gab gae gag gai gao gba gbe gbg gbi gbo ge- gea geb gee geg gei geo gga ggb ggg ggi ggo gia gib gie gig gii gio goa gob goe gog goi goo ia- iaa iab iae iag iai iao iba ibb ibe ibg ibi ibo ie- iea iee ieg iei iga igb ige igg igi igo iia iib iie iii iio io- ioa iob ioe iog ioi ioo o-i oaa oab oae oag oai oao ob- oba obb obe obg obi obo oea oeb oee oeg oei oeo oga oge ogg ogi ogo oia oib oie oii oio oo- ooa oob oog ooi ooo