-er bbb bbc bbe bbf bbn bbo bbr bcb bcc bce bcf bcn bco bcr be- beb bec bee bef ben beo ber bfb bfc bfe bff bfn bfo bfr bnb bnc bne bnf bnn bno bnr bob boc boe bof bon boo bor brb bre brf brn bro brr c-- cbb cbc cbe cbf cbn cbo cbr ccb ccc cce ccf ccn cco ccr ce- ceb cec cee cef cen ceo cer cfb cfc cfe cff cfn cfo cfr cn- cnb cnc cne cnf cnn cno cnr co- cob coc coe cof con coo cor crb crc cre crf crn cro crr ebb ebc ebe ebf ebn ebo ebr ec- ecb ecc ece ecf ecn eco ecr eeb eec eee eef een eeo eer ef- efb efc efe eff efo efr en- enb enc ene enf enn eno enr eo- eob eoc eoe eof eon eoo eor erb erc ere erf ern ero err fbb fbc fbe fbf fbn fbo fbr fcb fcc fce fcf fcn fco fcr feb fec fee fef fen feo fer ffc ffe fff ffn ffo ffr fnb fnc fne fnf fnn fnr fob foc foe fof fon foo for frb frc fre frf frn fro frr nbb nbc nbe nbf nbn nbo nbr ncb ncc nce ncf ncn nco ncr ne- neb nec nee nef nen neo ner nfb nfc nfe nff nfn nfo nfr nnb nnc nne nnf nnn nno no- nob noc noe nof non noo nor nrb nrc nre nrf nrn nro nrr ob- obb obc obe obf obn obo obr oc- ocb occ ocf ocn oco ocr oeb oec oee oef oen oeo oer of- ofb ofc ofe off ofn ofo ofr on- onb onc one onf onn ono onr oo- oob ooc oof oon ooo oor or- orb orc ore orf orn oro orr rbb rbc rbe rbf rbn rbo rbr rcb rcc rce rcf rcn rco rcr re- reb rec ree ref ren reo rer rfb rfc rfe rff rfn rfo rfr rnb rnc rnn rno rnr rob roc roe rof ron roo ror rrb rrc rrf rrn rrr