-er bbb bbc bbe bbf bbm bbo bbr bcb bcc bce bcf bcm bco bcr be- beb bec bee bef bem beo ber bfb bfc bfe bff bfm bfo bfr bmb bmc bme bmf bmm bmo bmr bob boc boe bof bom boo bor brb bre brf brm bro brr c-- cbb cbc cbe cbf cbm cbo cbr ccb ccc cce ccf ccm cco ccr ce- ceb cec cee cef cem ceo cer cfb cfc cfe cff cfm cfo cfr cmb cmc cme cmf cmm cmo cmr co- cob coc coe cof com coo cor crb crc cre crf crm cro crr ebb ebc ebe ebf ebm ebo ebr ec- ecb ecc ece ecf ecm eco ecr eeb eec eee eef eem eeo eer ef- efb efc efe eff efm efo efr em- emb emc eme emf emm emo emr eo- eob eoc eoe eof eom eoo eor erb erc ere erf erm ero err fbb fbc fbe fbf fbm fbo fbr fcb fcc fce fcf fcm fco fcr feb fec fee fef fem feo fer ffc ffe fff ffm ffo ffr fmb fmc fme fmf fmm fmo fmr fob foc foe fof fom foo for frb frc fre frf frm fro frr m-f m-o m-r mbb mbc mbe mbf mbm mbo mbr mc- mcb mcc mce mcf mcm mco mcr meb mec mee mef mem meo mer mfb mfc mfe mff mfm mfo mfr mmb mmc mme mmf mmm mmo mmr mob moc moe mof mom moo mor mrb mrc mre mrf mrm mro mrr ob- obb obc obe obf obm obo obr oc- ocb occ ocf ocm oco ocr oeb oec oee oef oem oeo oer of- ofb ofc ofe off ofm ofo ofr om- omb omc ome omf omm omo omr oo- oob ooc oof oom ooo oor or- orb orc ore orf orm oro orr rbb rbc rbe rbf rbm rbo rbr rcb rcc rce rcf rcm rco rcr re- reb rec ree ref rem reo rer rfb rfc rfe rff rfm rfo rfr rmb rmc rme rmf rmm rmo rmr rob roc roe rof rom roo ror rrb rrc rrf rrm rrr