-er -ic b-u bbb bbc bbe bbi bbr bbs bbt bbu bcb bcc bce bci bcr bcs bct bcu be- beb bec bee bei ber bes bet beu bi- bib bic bie bii bir bis bit biu brb bre bri brr brs brt bru bsb bsc bse bsi bsr bss bst bsu btb btc bte bti btr bts btt btu bub buc bue bui bur bus but buu c-- cbb cbc cbe cbi cbr cbs cbt cbu ccb ccc cce cci ccr ccs cct ccu ce- ceb cec cee cei cer ces cet ceu ci- cib cic cie cii cir cis cit ciu crb crc cre cri crr crs crt cru csb csc cse csi csr css cst csu ctb ctc cte cti ctr cts ctt ctu cub cuc cue cui cur cus cut cuu ebb ebc ebe ebi ebr ebs ebt ebu ec- ecb ecc ece eci ecr ecs ect ecu eeb eec eee eer ees eet eib eic eie eii eir eis eit eiu erb erc ere eri err ers ert eru es- esb esc ese esi esr ess est esu etb etc ete eti etr ets ett etu eu- eub euc eue eui eur eus eut ibb ibc ibe ibi ibr ibs ibt ibu icb icc ice ici icr ics ict icu ie- iec iee iei ier ies iet iib iic iie iii iir iis iit iiu ir- irb irc ire iri irr irs irt iru is- isb isc ise isi isr iss ist isu itb itc ite iti its itt itu iu- iub iuc iue iui iur ius iut rbb rbc rbe rbi rbr rbs rbt rbu rcb rcc rce rci rcr rcs rct rcu re- reb rec ree rei rer res ret reu rib ric rie rii rir ris rit rrb rrc rri rrr rrs rrt rru rsb rsc rse rsi rsr rss rst rsu rtb rtc rte rti rtr rts rtt rtu rub ruc rue rui rur rus rut ruu sbb sbc sbe sbi sbr sbs sbt sbu scb scc sce sci scr scs sct scu se- seb sec see sei ser ses set seu sib sic sie sii sir sis sit siu sr- srb src sre sri srr srs srt ss- ssb ssc sse ssi ssr sss sst ssu stb stc ste sti str sts stt stu sub suc sue sui sur sus sut suu tbb tbc tbe tbi tbr tbs tbt tbu tcb tcc tce tci tcr tcs tct tcu te- teb tec tee tei ter tes tet teu tib tic tie tii tir tis tit tiu trb trc tre tri trr trs trt tru tsb tsc tse tsi tsr tss tst tsu ttb ttc tte tti ttr tts ttt ttu tub tuc tue tui tur tus tut tuu ubb ubc ube ubi ubr ubs ubt ubu ucb ucc uce uci ucr ucs uct ucu ueb uec uee uei uer ues uet uib uic uie uii uir uis uit uiu ur- urb urc ure uri urr urs urt uru usb usc use usi usr uss ust usu utb utc ute uti utr uts utt utu uuc uue uur uus uut uuu