b-u bbb bbi bbm bbr bbs bbt bbu bi- bib bii bim bir bis bit biu bmb bmi bmm bmr bms bmt bmu brb bri brm brr brs brt bru bsb bsi bsm bsr bss bst bsu btb bti btm btr bts btt btu bub bui bum bur bus but buu ibb ibi ibm ibr ibs ibt ibu iib iii iim iir iis iit iiu im- imb imi imm ims imt imu ir- irb iri irm irr irs irt iru is- isb isi ism isr iss ist isu itb iti itm its itt itu iu- iub iui ium iur ius iut m-r mbb mbi mbm mbr mbs mbt mbu mi- mib mii mim mir mis mit miu mmb mmi mmm mmr mms mmt mmu mrb mri mrm mrr mrs mrt mru msb msi msm msr mss mst msu mtb mti mtm mtr mts mtt mtu mub mui mum mur mus mut muu rbb rbi rbm rbr rbs rbt rbu rib rii rim rir ris rit rmb rmi rmm rmr rms rmt rrb rri rrm rrr rrs rrt rru rsb rsi rsm rsr rss rst rsu rtb rti rtm rtr rts rtt rtu rub rui rum rur rus rut ruu sbb sbi sbm sbr sbs sbt sbu sib sii sim sir sis sit siu smb smi smm smr sms smt smu sr- srb sri srm srr srs srt ss- ssb ssi ssm ssr sss sst ssu stb sti stm str sts stt stu sub sui sum sur sus sut suu tbb tbi tbm tbr tbs tbt tbu tib tii tim tir tis tit tiu tmb tmi tmm tmr tms tmt tmu trb tri trm trr trs trt tru tsb tsi tsm tsr tss tst tsu ttb tti ttm ttr tts ttt ttu tub tui tum tur tus tut tuu ubb ubi ubr ubs ubt ubu uib uii uim uir uis uit uiu um- umb umi umm umr ums umt umu ur- urb uri urm urr urs urt uru usb usi usm usr uss ust usu utb uti utm utr uts utt utu uum uur uus uut uuu