b-u bbb bbf bbg bbo bbu bfb bff bfg bfo bfu bfz bgb bgf bgg bgo bgu bgz bob bof bog boo bou boz bub buf bug buo buu buz bzf bzo bzu bzz fbb fbf fbg fbo fbu fff ffg ffo ffu ffz fgb fgf fgg fgz fob fof fog foo fou foz fub fuf fug fuo fuu gbf gbg gbo gbu gbz gfb gff gfo gfz ggb ggg ggo ggu ggz gob gof gog goo gou goz gu- gub guf gug guo guu guz gzo gzu ob- obb obf obg obo obu of- ofb off ofg ofo ofu ofz ogf ogg ogo oo- oob oof oog ooo ou- ouf ouo ozo ozu ozz ubb ubf ubg ubo ubu uff ufg ufo ufu ugb ugf ugg ugo ugu uob uog uoo uug uuu uzb uzo uzu z-g zbb zgb zgg zo- zob zof zog zoo zou zub zug zuz zzz