-er b-u bbb bbe bbi bbk bbr bbs bbt bbu be- beb bee bei bek ber bes bet beu bi- bib bie bii bik bir bis bit biu bkb bke bkk bkr bks bkt brb bre bri brk brr brs brt bru bsb bse bsi bsk bsr bss bst bsu btb bte bti btk btr bts btt btu bub bue bui buk bur bus but buu ebb ebe ebi ebk ebr ebs ebt ebu eeb eee eek eer ees eet eib eie eii eik eir eis eit eiu ekb eke eki ekr eks ekt eku erb ere eri erk err ers ert eru es- esb ese esi esk esr ess est esu etb ete eti etk etr ets ett etu eu- eub eue eui eur eus eut ibb ibe ibi ibk ibr ibs ibt ibu ie- iee iei iek ier ies iet iib iie iii iir iis iit iiu ikb ike iki ikk ikr iks ikt iku ir- irb ire iri irk irr irs irt iru is- isb ise isi isk isr iss ist isu itb ite iti itk its itt itu iu- iub iue iui iur ius iut k-t kbb kbe kbi kbk kbr kbs kbu ke- keb kee kei kek ker kes ket kib kie kii kik kir kis kit kiu kkb kke kki kkk kkr kks kkt kku kri krk krr krs krt kru ksb kse ksi ksk ksr kss kst ksu ktb kte ktk ktr kts ktt ktu kub kue kui kuk kur kus kut kuu rbb rbe rbi rbk rbr rbs rbt rbu re- reb ree rei rek rer res ret reu rib rie rii rik rir ris rit rkb rke rkk rks rkt rku rrb rri rrk rrr rrs rrt rru rsb rse rsi rsk rsr rss rst rsu rtb rte rti rtk rtr rts rtt rtu rub rue rui ruk rur rus rut ruu sbb sbe sbi sbk sbr sbs sbt sbu se- seb see sei sek ser ses set seu sib sie sii sik sir sis sit siu sk- skb ske ski skk skr sks skt sku sr- srb sre sri srk srr srs srt ss- ssb sse ssi ssk ssr sss sst ssu stb ste sti stk str sts stt stu sub sue sui suk sur sus sut suu tbb tbe tbi tbk tbr tbs tbt tbu te- teb tee tei tek ter tes tet teu tib tie tii tik tir tis tit tiu tkb tke tkk tkr tks tkt trb tre tri trk trr trs trt tru tsb tse tsi tsk tsr tss tst tsu ttb tte tti ttk ttr tts ttt ttu tub tue tui tuk tur tus tut tuu ubb ube ubi ubk ubr ubs ubt ubu ueb uee uei uer ues uet uib uie uii uir uis uit uiu ukb uke uki ukk ukr uku ur- urb ure uri urk urr urs urt uru usb use usi usk usr uss ust usu utb ute uti utk utr uts utt utu uue uur uus uut uuu