bbb bbe bbk bbn bbo be- beb bee bek ben beo bez bkb bke bkk bkn bko bnb bne bnk bnn bno bnz bob boe bok bon boo boz bze bzn bzo bzz ebb ebe ebk ebn ebo eeb eee eek een eeo ekb eke eko en- enb ene enk enn eno enz eo- eob eoe eok eon eoo eze ezo ezz k-z kbb kbe kbk kbn kbo kbz ke- keb kee kek ken keo kez kkb kke kkk kkn kn- kne knk knn kno kob koe kok kon koo koz kzo nbb nbe nbk nbn nbo ne- neb nee nek nen neo nez nke nkk nkn nko nnb nne nnk nnn nno nnz no- nob noe nok non noo noz nzb nze nzo nzz ob- obb obe obk obn obo oeb oee oen oeo okb oke okk oko on- onb one onk onn ono oo- oob ook oon ooo oze ozo ozz zbb zeb zee zek zen zeo zez zne znn zno zo- zob zoe zok zon zoo zzz