-er -ic bbb bbc bbe bbi bbk bbr bbs bcb bcc bce bci bck bcr bcs be- beb bec bee bei bek ber bes bi- bib bic bie bii bik bir bis bkb bkc bke bkk bkr bks brb bre bri brk brr brs bsb bsc bse bsi bsk bsr bss c-- cbb cbc cbe cbi cbk cbr cbs ccb ccc cce cci cck ccr ccs ce- ceb cec cee cei cek cer ces ci- cib cic cie cii cik cir cis ckb ckc cki cks crb crc cre cri crk crr crs csb csc cse csi csk csr css ebb ebc ebe ebi ebk ebr ebs ec- ecb ecc ece eci eck ecr ecs eeb eec eee eek eer ees eib eic eie eii eik eir eis ekb ekc eke eki ekr eks erb erc ere eri erk err ers es- esb esc ese esi esk esr ess ibb ibc ibe ibi ibk ibr ibs icb icc ice ici ick icr ics ie- iec iee iei iek ier ies iib iic iie iii iir iis ikb ikc ike iki ikk ikr iks ir- irb irc ire iri irk irr irs is- isb isc ise isi isk isr iss kbb kbc kbe kbi kbk kbr kbs kcb kcc kce kci kck kcr kcs ke- keb kec kee kei kek ker kes kib kic kie kii kik kir kis kkb kkc kke kki kkk kkr kks krc kri krk krr krs ksb ksc kse ksi ksk ksr kss rbb rbc rbe rbi rbk rbr rbs rcb rcc rce rci rcr rcs re- reb rec ree rei rek rer res rib ric rie rii rik rir ris rkb rkc rke rkk rks rrb rrc rri rrk rrr rrs rsb rsc rse rsi rsk rsr rss sbb sbc sbe sbi sbk sbr sbs scb scc sce sci sck scr scs se- seb sec see sei sek ser ses sib sic sie sii sik sir sis sk- skb skc ske ski skk skr sks sr- srb src sre sri srk srr srs ss- ssb ssc sse ssi ssk ssr sss