-er bbb bbc bbe bbm bbn bbr bcb bcc bce bcm bcn bcr be- beb bec bee bem ben ber bmb bmc bme bmm bmn bmr bnb bnc bne bnn bnr brb bre brm brn brr c-- cbb cbc cbe cbm cbn cbr ccb ccc cce ccm ccn ccr ce- ceb cec cee cem cen cer cmb cmc cme cmm cmn cmr cn- cnb cnc cne cnm cnn cnr crb crc cre crm crn crr ebb ebc ebe ebm ebn ebr ec- ecb ecc ece ecm ecn ecr eeb eec eee eem een eer em- emb emc eme emm emn emr en- enb enc ene enm enn enr erb erc ere erm ern err m-r mbb mbc mbe mbm mbr mc- mcb mcc mce mcm mcn mcr meb mec mee mem men mer mmb mmc mme mmm mmn mmr mnb mnc mne mnm mnn mnr mrb mrc mre mrm mrn mrr nbb nbc nbe nbm nbn nbr ncb ncc nce ncm ncn ncr ne- neb nec nee nem nen ner nmb nmc nme nmm nmn nmr nnb nnc nne nnm nnn nrb nrc nre nrm nrn nrr rbb rbc rbe rbm rbn rbr rcb rcc rce rcm rcn rcr re- reb rec ree rem ren rer rmb rmc rme rmm rmn rmr rnb rnc rnm rnn rnr rrb rrc rrm rrn rrr