-er -ey bbb bbe bbk bbn bbr bby be- beb bee bek ben ber bey bkb bke bkk bkn bkr bnb bne bnk bnn bnr brb bre brk brn brr bry by- bye byk byn byr ebb ebe ebk ebn ebr eby eeb eee eek een eer eey ekb eke ekr eky en- enb ene enk enn enr eny erb ere erk ern err ery eye eyn eyr kbb kbe kbk kbn kbr ke- keb kee kek ken ker key kkb kke kkk kkn kkr kky kn- kne knk knn knr krk krn krr kry kye kyn kyr nbb nbe nbk nbn nbr ne- neb nee nek nen ner ney nke nkk nkn nkr nky nnb nne nnk nnn nrb nre nrk nrn nrr nry nye nyk nyn nyy rbb rbe rbk rbn rbr re- reb ree rek ren rer rey rkb rke rkk rky rnb rnn rnr rny rrb rrk rrn rrr ry- rye ryk ryn ryr ryy ybe ybr yby yeb yee yek yen yer yey ykk ykn yne ynk ynn yny yre yrn yyb yye yyy