b-u bbb bbi bbk bbr bbs bbt bbu bi- bib bii bik bir bis bit biu bkb bkk bkr bks bkt brb bri brk brr brs brt bru bsb bsi bsk bsr bss bst bsu btb bti btk btr bts btt btu bub bui buk bur bus but buu ibb ibi ibk ibr ibs ibt ibu iib iii iir iis iit iiu ikb iki ikk ikr iks ikt iku ir- irb iri irk irr irs irt iru is- isb isi isk isr iss ist isu itb iti itk its itt itu iu- iub iui iur ius iut k-t kbb kbi kbk kbr kbs kbu kib kii kik kir kis kit kiu kkb kki kkk kkr kks kkt kku kri krk krr krs krt kru ksb ksi ksk ksr kss kst ksu ktb ktk ktr kts ktt ktu kub kui kuk kur kus kut kuu rbb rbi rbk rbr rbs rbt rbu rib rii rik rir ris rit rkb rkk rks rkt rku rrb rri rrk rrr rrs rrt rru rsb rsi rsk rsr rss rst rsu rtb rti rtk rtr rts rtt rtu rub rui ruk rur rus rut ruu sbb sbi sbk sbr sbs sbt sbu sib sii sik sir sis sit siu sk- skb ski skk skr sks skt sku sr- srb sri srk srr srs srt ss- ssb ssi ssk ssr sss sst ssu stb sti stk str sts stt stu sub sui suk sur sus sut suu tbb tbi tbk tbr tbs tbt tbu tib tii tik tir tis tit tiu tkb tkk tkr tks tkt trb tri trk trr trs trt tru tsb tsi tsk tsr tss tst tsu ttb tti ttk ttr tts ttt ttu tub tui tuk tur tus tut tuu ubb ubi ubk ubr ubs ubt ubu uib uii uir uis uit uiu ukb uki ukk ukr uku ur- urb uri urk urr urs urt uru usb usi usk usr uss ust usu utb uti utk utr uts utt utu uur uus uut uuu