bbb bbe bbf bbn bbo bbx be- beb bee bef ben beo bex bfb bfe bff bfn bfo bfx bnb bne bnf bnn bno bnx bob boe bof bon boo box bxb bxn bxo bxx ebb ebe ebf ebn ebo ebx eeb eee eef een eeo eex ef- efb efe eff efo efx en- enb ene enf enn eno eo- eob eoe eof eon eoo ex- exe exo exx fbb fbe fbf fbn fbo fbx feb fee fef fen feo fex ffe fff ffn ffo ffx fnb fne fnf fnn fnx fob foe fof fon foo fox fxe fxx nbb nbe nbf nbn nbo nbx ne- neb nee nef nen neo nex nfb nfe nff nfn nfo nnb nne nnf nnn nno no- nob noe nof non noo nox ob- obb obe obf obn obo obx oeb oee oef oen oeo oex of- ofb ofe off ofn ofo ofx on- onb one onf onn ono onx oo- oob oof oon ooo oox ox- oxb oxf oxn oxo oxx xbe xbx xee xen xex xfe xfn xfx xno xof xon xoo xox xxo xxx