-er -ic bbb bbc bbe bbi bbk bbn bbr bbs bcb bcc bce bci bck bcn bcr bcs be- beb bec bee bei bek ben ber bes bi- bib bic bie bii bik bin bir bis bkb bkc bke bkk bkn bkr bks bnb bnc bne bni bnk bnn bnr bns brb bre bri brk brn brr brs bsb bsc bse bsi bsk bsn bsr bss c-- cbb cbc cbe cbi cbk cbn cbr cbs ccb ccc cce cci cck ccn ccr ccs ce- ceb cec cee cei cek cen cer ces ci- cib cic cie cii cik cin cir cis ckb ckc cki cks cn- cnb cnc cne cni cnn cnr cns crb crc cre cri crk crn crr crs csb csc cse csi csk csn csr css ebb ebc ebe ebi ebk ebn ebr ebs ec- ecb ecc ece eci eck ecn ecr ecs eeb eec eee eek een eer ees eib eic eie eii eik ein eir eis ekb ekc eke eki ekr eks en- enb enc ene eni enk enn enr ens erb erc ere eri erk ern err ers es- esb esc ese esi esk esn esr ess ibb ibc ibe ibi ibk ibn ibr ibs icb icc ice ici ick icn icr ics ie- iec iee iei iek ien ier ies iib iic iie iii iin iir iis ikb ikc ike iki ikk ikr iks in- inb inc ine ini ink inn inr ins ir- irb irc ire iri irk irn irr irs is- isb isc ise isi isk isn isr iss kbb kbc kbe kbi kbk kbn kbr kbs kcb kcc kce kci kck kcn kcr kcs ke- keb kec kee kei kek ken ker kes kib kic kie kii kik kin kir kis kkb kkc kke kki kkk kkn kkr kks kn- knc kne kni knk knn knr krc kri krk krn krr krs ksb ksc kse ksi ksk ksn ksr kss n-i nbb nbc nbe nbi nbk nbn nbr nbs ncb ncc nce nci nck ncn ncr ncs ne- neb nec nee nei nek nen ner nes nib nic nie nii nik nin nir nis nkc nke nki nkk nkn nkr nks nnb nnc nne nni nnk nnn nns nrb nrc nre nri nrk nrn nrr nrs nsb nsc nse nsi nsk nsn nsr nss rbb rbc rbe rbi rbk rbn rbr rbs rcb rcc rce rci rcn rcr rcs re- reb rec ree rei rek ren rer res rib ric rie rii rik rin rir ris rkb rkc rke rkk rks rnb rnc rni rnn rnr rns rrb rrc rri rrk rrn rrr rrs rsb rsc rse rsi rsk rsn rsr rss sbb sbc sbe sbi sbk sbn sbr sbs scb scc sce sci sck scn scr scs se- seb sec see sei sek sen ser ses sib sic sie sii sik sin sir sis sk- skb skc ske ski skk skr sks snb snc sne sni snk snn snr sns sr- srb src sre sri srk srn srr srs ss- ssb ssc sse ssi ssk ssn ssr sss