-ene bbbb bbeb bbrc bcbc bccc bcec bcer bebb bebe beeb been beer bene benn berc bere bern berr bner bnrr brcb brce breb brec bree bren brer brrr cbbc cbcc cbce cbcn cbcr cbec cbee cber cbre cbrn ccbc ccbn cccb cccc ccee ccnb ccnc ccne ccnr ccrc ccre cec- cece ceeb ceec cen- cene cer- cerc cere cern cnbc cnrc cnrr crbc crcc crce crcr cre- creb crec cree cren crne ebbc ebbr ebcc eben eber ecbc ecbe eccb eccc ecce ecne ecrc ecrr eeee eerc enb- enbn enbr ence enee ener ennc enne erbb erbe ercc erce ereb erec eren erer erne errc erre nbbc nbcc nber ncbc nccc nccn nccr ncec ncee ncen ncer ncnc ncrc ncre nebb nebe nebn nebr necc nece necr neeb neen neer nene nerc nere nerr nnnn nren nrrc rbbb rbbr rcbc rccb rccc rcnr rebb rebe recc rece recr reeb reen rene renn rere rnbr rrrr