b-u bbb bbf bbo bbr bbs bbt bbu bfb bff bfo bfr bfs bft bfu bob bof boo bor bos bot bou brb brf bro brr brs brt bru bsb bsf bso bsr bss bst bsu btb btf bto btr bts btt btu bub buf buo bur bus but buu fbb fbf fbo fbr fbs fbt fbu fff ffo ffr ffs fft ffu fob fof foo for fos fot fou frb frf fro frr frs frt fru fsb fsf fso fsr fss fst fsu ftb ftf fto ftr fts ftt ftu fub fuf fuo fur fus fut fuu ob- obb obf obo obr obs obt obu of- ofb off ofo ofr ofs oft ofu oo- oob oof ooo oor oos oot or- orb orf oro orr ors ort oru os- osb osf oso osr oss ost osu ot- otb otf oto otr ots ott otu ou- ouf ouo our ous out rbb rbf rbo rbr rbs rbt rbu rfb rff rfo rfr rfs rft rfu rob rof roo ror ros rot rou rrb rrf rrr rrs rrt rru rsb rsf rso rsr rss rst rsu rtb rtf rto rtr rts rtt rtu rub ruf ruo rur rus rut ruu sbb sbf sbo sbr sbs sbt sbu sfb sff sfo sfr sfs sft sfu sob sof soo sor sos sot sou sr- srb srf sro srr srs srt ss- ssb ssf sso ssr sss sst ssu stb stf sto str sts stt stu sub suf suo sur sus sut suu tbb tbf tbo tbr tbs tbt tbu tfb tff tfo tfr tfs tft tfu to- tob tof too tor tos tot tou trb trf tro trr trs trt tru tsb tsf tso tsr tss tst tsu ttb ttf tto ttr tts ttt ttu tub tuf tuo tur tus tut tuu ubb ubf ubo ubr ubs ubt ubu uff ufo ufr ufs uft ufu uob uoo uor uos uot ur- urb urf uro urr urs urt uru usb usf uso usr uss ust usu utb utf uto utr uts utt utu uur uus uut uuu

-ous bbbb bbbs bffs bfsr bfts bftt bobb bobo bobs bobu boff bofs bofu boob boof boor boos boot bor- borf boro borr bors bort boru boso boss bost bosu botb boto bots bott bouf bour bous bout brfu brob broo bror bros brot brou brrr brrs brsb brsr brst brus brut bsff bsfs bsos bsts btob btor btrt btss bttb btus bubb bubo bubs bubu buff bufo bufr bur- burb buro burr burs burt buru buss bust busu but- buto buts butt buus fbrs fbus ffff ffrr ffss fftf fobs fobt fofo foof foos foot for- forb foro forr fors fort fosb foso foss fost foto fots fott four fous fout frob fros frot frou frsb frso frst frub fsfo fssf ftos ftrs ftsr ftub fubb fubs fubu fuff fufu fuor fur- furo furr furs furt fuso fuss fust fusu futo futs futu obbo obor obos obot obro obsr obss obst obts obus off- offo offr offs offu ofor ofst ofus ooff oofs oooo ooos oort oost ootb oots oous orbb orbo orbs orbu orff orfs orfu oro- orof oror oros orot orro orrs orso orsu orto orts orub orus osoo osor osos osro ossb osso ossu ostr osts otbs oto- otof otoo otor otos otro otrs otso otsu otto otts ottu otur otus oubs ouff our- ouro ours ourt oust out- outb outo outs ouu- rbbb rbbr rbbs rbss rbst rob- robb robo robs robt robu roff rofo roob roof roor roos root roro rort roru roso ross rost roto rotr rots rott roub rouf rous rout rrrr rsos rsts rstu rtbf rtfb rtss rtts rubb rubs rubu ruff rufo ruft ruro rurs ruru ruso russ rust rusu ruto ruts rutt rutu s-os sbbs sbor sbot sbst sbus sfor sfos sfro sfss sfsu sfts sobo sobr sobs sobt sobu sofo soft soof soor soos soot sorb soro sorr sors sort soru soso soss sost soto sots sotu souf sour sous sout sros srtr srub ssbr ssot ssrs sssb sssf ssss sstb ssts stbs stfu stob stof stoo stor stos stot stou stro strs stru stsf stss sttr stub stuf stur stus stut sub- subb subo subs suf- suff sufr sufs sufu suor suos sur- surf suro surr surs surt suru sus- suso suss sust susu suto sutu suus tbbs tbrb tbst tfot tfrs tfss tobo tobs tobt tobu toff tofo toft tofu toof toor toos toot torf toro torr tors tort toru tosb toso toss tost tosu toto totr tots tott tour tous tout trfr troo tros trot trou trst trtr trub trus trut truu tsob tsos tsou tssf tssr tsst tsts ttbb ttff ttss tttt tubb tubo tubr tubs tubu tuff tufo tuft tufu tuor tuos turb turf turo turr turs turt turu tuss tust tuto tuts tutt tutu tuuo ubbo ubos ubtf ufos uofo uor- urbs urff urft uro- uroo urso urss ursu urts urur urus urut usbr usbs usfs usos ussb ussf ussr usss usst ussu ustb usto usts usus utfo utor utto uttu uutf uuuu

bbuss bo-bo bobos bobr bobst bobts boffo boffs boobs boofs boors boort booru boost boots borbo boro- boroo boros borot borou borro borst borsu borts borus borut bosor bosso bosut botos botou botro botts bottu botus bours boust bouto bouts brobo brobs broft broos bross broto brous brout brrrr bruff bruss brust bsoft bsous btr-t btrfs btstu buffo buffs bufos burbs buroo buros burro burrs burru burst burts burtt burus burut busot busso bussu busto busts busur busut busuu buto- butor butot butou butts butuo butut fofos foots forbs foros forro forso forss forst forto forts forur forus fotos fotur fotus fourb fouro fours foust fouts frobs froot frost frots frust fruto ftrtt fu-fu fubbs fubus fuffs furbo furo- furor furrs furst furus fuso- fusor fusts fusus futsu futur o-r-b oboro obout obtus offof offto ofosu ofoto ofour ooooo ootus orbot orbus orfor orobo oroso orost orosu orout ortoo oruro orust orutu ososo ossos ossur ostro