-er -ic bbb bbc bbe bbi bbk bbn bbo bbr bcb bcc bce bci bck bcn bco bcr be- beb bec bee bei bek ben beo ber bi- bib bic bie bii bik bin bio bir bkb bkc bke bkk bkn bko bkr bnb bnc bne bni bnk bnn bno bnr bob boc boe boi bok bon boo bor brb bre bri brk brn bro brr c-- cbb cbc cbe cbi cbk cbn cbo cbr ccb ccc cce cci cck ccn cco ccr ce- ceb cec cee cei cek cen ceo cer ci- cib cic cie cii cik cin cio cir ckb ckc cki cko cn- cnb cnc cne cni cnn cno cnr co- cob coc coe coi cok con coo cor crb crc cre cri crk crn cro crr ebb ebc ebe ebi ebk ebn ebo ebr ec- ecb ecc ece eci eck ecn eco ecr eeb eec eee eek een eeo eer eib eic eie eii eik ein eio eir ekb ekc eke eki eko ekr en- enb enc ene eni enk enn eno enr eo- eob eoc eoe eoi eok eon eoo eor erb erc ere eri erk ern ero err ibb ibc ibe ibi ibk ibn ibo ibr icb icc ice ici ick icn ico icr ie- iec iee iei iek ien ier iib iic iie iii iin iio iir ikb ikc ike iki ikk iko ikr in- inb inc ine ini ink inn ino inr io- iob ioc ioe ioi ion ioo ior ir- irb irc ire iri irk irn iro irr kbb kbc kbe kbi kbk kbn kbo kbr kcb kcc kce kci kck kcn kcr ke- keb kec kee kei kek ken keo ker kib kic kie kii kik kin kio kir kkb kkc kke kki kkk kkn kkr kn- knc kne kni knk knn kno knr kob koc koe koi kok kon koo kor krc kri krk krn kro krr n-i nbb nbc nbe nbi nbk nbn nbo nbr ncb ncc nce nci nck ncn nco ncr ne- neb nec nee nei nek nen neo ner nib nic nie nii nik nin nio nir nkc nke nki nkk nkn nko nkr nnb nnc nne nni nnk nnn nno no- nob noc noe noi nok non noo nor nrb nrc nre nri nrk nrn nro nrr o-i ob- obb obc obe obi obk obn obo obr oc- ocb occ oci ock ocn oco ocr oeb oec oee oei oen oeo oer oib oic oie oii oik oin oio oir okb okc oke oki okk oko okr on- onb onc one oni onk onn ono onr oo- oob ooc ooi ook oon ooo oor or- orb orc ore ori ork orn oro orr rbb rbc rbe rbi rbk rbn rbo rbr rcb rcc rce rci rcn rco rcr re- reb rec ree rei rek ren reo rer rib ric rie rii rik rin rio rir rkb rkc rke rkk rko rnb rnc rni rnn rno rnr rob roc roe roi rok ron roo ror rrb rrc rri rrk rrn rrr