-er -ic bbb bbc bbe bbi bbk bbr bbs bbt bcb bcc bce bci bck bcr bcs bct be- beb bec bee bei bek ber bes bet bi- bib bic bie bii bik bir bis bit bkb bkc bke bkk bkr bks bkt brb bre bri brk brr brs brt bsb bsc bse bsi bsk bsr bss bst btb btc bte bti btk btr bts btt c-- cbb cbc cbe cbi cbk cbr cbs cbt ccb ccc cce cci cck ccr ccs cct ce- ceb cec cee cei cek cer ces cet ci- cib cic cie cii cik cir cis cit ckb ckc cki cks ckt crb crc cre cri crk crr crs crt csb csc cse csi csk csr css cst ctb ctc cte cti ctk ctr cts ctt ebb ebc ebe ebi ebk ebr ebs ebt ec- ecb ecc ece eci eck ecr ecs ect eeb eec eee eek eer ees eet eib eic eie eii eik eir eis eit ekb ekc eke eki ekr eks ekt erb erc ere eri erk err ers ert es- esb esc ese esi esk esr ess est etb etc ete eti etk etr ets ett ibb ibc ibe ibi ibk ibr ibs ibt icb icc ice ici ick icr ics ict ie- iec iee iei iek ier ies iet iib iic iie iii iir iis iit ikb ikc ike iki ikk ikr iks ikt ir- irb irc ire iri irk irr irs irt is- isb isc ise isi isk isr iss ist itb itc ite iti itk its itt k-t kbb kbc kbe kbi kbk kbr kbs kcb kcc kce kci kck kcr kcs kct ke- keb kec kee kei kek ker kes ket kib kic kie kii kik kir kis kit kkb kkc kke kki kkk kkr kks kkt krc kri krk krr krs krt ksb ksc kse ksi ksk ksr kss kst ktb ktc kte ktk ktr kts ktt rbb rbc rbe rbi rbk rbr rbs rbt rcb rcc rce rci rcr rcs rct re- reb rec ree rei rek rer res ret rib ric rie rii rik rir ris rit rkb rkc rke rkk rks rkt rrb rrc rri rrk rrr rrs rrt rsb rsc rse rsi rsk rsr rss rst rtb rtc rte rti rtk rtr rts rtt sbb sbc sbe sbi sbk sbr sbs sbt scb scc sce sci sck scr scs sct se- seb sec see sei sek ser ses set sib sic sie sii sik sir sis sit sk- skb skc ske ski skk skr sks skt sr- srb src sre sri srk srr srs srt ss- ssb ssc sse ssi ssk ssr sss sst stb stc ste sti stk str sts stt tbb tbc tbe tbi tbk tbr tbs tbt tcb tcc tce tci tck tcr tcs tct te- teb tec tee tei tek ter tes tet tib tic tie tii tik tir tis tit tkb tkc tke tkk tkr tks tkt trb trc tre tri trk trr trs trt tsb tsc tse tsi tsk tsr tss tst ttb ttc tte tti ttk ttr tts ttt