a-a a-b a-z aaa aab aag aao aaz ab- aba abb abg abo abz ag- aga agb agg ago agz aoa aob aog aoo az- aza azb azg azo azz baa bab bag bao baz bba bbb bbg bbo bga bgb bgg bgo bgz boa bob bog boo boz bza bzo bzz gaa gab gag gao gaz gba gbg gbo gbz gga ggb ggg ggo ggz goa gob gog goo goz gza gzo oaa oab oag oao ob- oba obb obg obo oga ogg ogo oo- ooa oob oog ooo oza ozo ozz z-g zaa zab zag zao zaz zbb zgb zgg zo- zoa zob zog zoo zzz