-er -ic bbb bbc bbe bbi bbk bbl bbr bbs bcb bcc bce bci bck bcl bcr bcs be- beb bec bee bei bek bel ber bes bi- bib bic bie bii bik bil bir bis bkb bkc bke bkk bkl bkr bks blb blc ble bli blk bll blr bls brb bre bri brk brl brr brs bsb bsc bse bsi bsk bsl bsr bss c-- cbb cbc cbe cbi cbk cbl cbr cbs ccb ccc cce cci cck ccl ccr ccs ce- ceb cec cee cei cek cel cer ces ci- cib cic cie cii cik cil cir cis ckb ckc cki cks cl- clb clc cle cli clk cll clr cls crb crc cre cri crk crl crr crs csb csc cse csi csk csl csr css ebb ebc ebe ebi ebk ebl ebr ebs ec- ecb ecc ece eci eck ecl ecr ecs eeb eec eee eek eel eer ees eib eic eie eii eik eil eir eis ekb ekc eke eki ekl ekr eks elb elc ele eli elk ell elr els erb erc ere eri erk erl err ers es- esb esc ese esi esk esl esr ess ibb ibc ibe ibi ibk ibl ibr ibs icb icc ice ici ick icl icr ics ie- iec iee iei iek iel ier ies iib iic iie iii iil iir iis ikb ikc ike iki ikk ikl ikr iks il- ilb ilc ile ili ilk ill ilr ils ir- irb irc ire iri irk irl irr irs is- isb isc ise isi isk isl isr iss kbb kbc kbe kbi kbk kbl kbr kbs kcb kcc kce kci kck kcl kcr kcs ke- keb kec kee kei kek kel ker kes kib kic kie kii kik kil kir kis kkb kkc kke kki kkk kkl kkr kks kl- klb klc kli klr kls krc kri krk krl krr krs ksb ksc kse ksi ksk ksl ksr kss lbb lbc lbe lbi lbk lbl lbr lbs lcb lcc lce lci lck lcl lcr lcs leb lec lee lei lek lel ler les lib lic lie lii lik lil lir lis lkb lkl lkr lks llb llc lle lli llk lll llr lls lrb lrc lri lrk lrr lrs lsb lsc lse lsi lsk lsl lsr lss rbb rbc rbe rbi rbk rbl rbr rbs rcb rcc rce rci rcl rcr rcs re- reb rec ree rei rek rel rer res rib ric rie rii rik ril rir ris rkb rkc rke rkk rks rlc rle rli rll rlr rls rrb rrc rri rrk rrl rrr rrs rsb rsc rse rsi rsk rsl rsr rss sbb sbc sbe sbi sbk sbl sbr sbs scb scc sce sci sck scl scr scs se- seb sec see sei sek sel ser ses sib sic sie sii sik sil sir sis sk- skb skc ske ski skk skl skr sks slb slc sle sli slk sll slr sls sr- srb src sre sri srk srl srr srs ss- ssb ssc sse ssi ssk ssl ssr sss