-ous bbbb bbbs bffs bfpo bfpp bfts bftt bobb bobo bobs bobu boff bofs bofu boob boof boop boos boot bopp bops boso boss bost bosu botb boto bots bott bouf boup bous bout bpot bpsu bptf bsff bsfs bsos bspp bsts bsup btbp btob btps btss bttb btus bubb bubo bubs bubu buff bufo bups buss bust busu but- buto buts butt buus fbop fbus ffff ffps ffss fftf fobs fobt fofo foof foos foot fopp fops fosb foso foss fost foto fotp fots fott foup fous fout fsfo fspf fssf fssp ftop ftos ftps ftub fubb fubs fubu fuff fufu fuso fuss fust fusu futo futs futu obbo obos obot obss obst obts obus off- offo offs offu ofst oftp ofus ooff oofs oooo ooos oops oost ootb ootp oots oous opo- opos oppo opps opsu opto opts opus osbp osoo osos ossb osso ossu osts otbs otfp oto- otof otoo otos otpp otso otsu otto otts ottu otus oubs ouff oust out- outb outo outs ouu- pbsp pfff pfft pfps pobo pobs poff poof poop poos poot pop- popo popp pops popt posb poso poss post potf poto pots pott potu pouf poup pous pout ppos pppo pppp ppps ppsf ppss ppts pptt psbt psfs psos psou pspp psps psso psst psts pstu ptop pubs pubu puff puft pups pupu puss pust put- puto puts putt putu s-os sbbs sbot sbsp sbst sbus sfos sfss sfsu sftp sfts sobo sobp sobs sobt sobu sofo soft soof soop soos soot sopo sopp sops sopu soso soss sost soto sotp sots sotu souf soup sous sout spfs spoo spop spos spot sppf spps spso spsp spss spst sptb spto spts spus sput ssfp ssop ssot sspf sspo ssps sspt sssb sssf ssss sstb sstp ssts stbs stfu stob stof stoo stop stos stot stou stpf stpp stps stsf stss stub stuf stup stus stut sub- subb subo subs suf- suff sufs sufu suos sup- supo supp sups supt sus- suso susp suss sust susu suto sutu suus tbbs tbsp tbst tbtp tfot tfpt tfss tftp tobo tobs tobt tobu toff tofo toft tofu toof toos toot top- topf topo topp tops topt topu tosb toso toss tost tosu toto tots tott toup tous tout tppp tptp tput tsob tsop tsos tsou tspo tsps tspt tssf tsst tsts tsup ttbb ttff ttop ttss tttt tubb tubo tubs tubu tuff tufo tuft tufu tuos tupo tups tupu tuss tust tuto tuts tutt tutu tuuo ubbo ubos ubtf ufos ufpb uftp uofo upos uppp uppu upto upup usbs usfs usos uspo uspp usps ussb ussf usss usst ussu ustb usto ustp usts usus utfo utto uttu uutf uuuu