srfc srnn srno sros srtr srub ssbn ssbr sscc sscs ssfc ssns ssoc ssot ssrc ssrs sssb sssc sssf ssss sstb sstc ssts stbc stbs stcc stcs stcu stfc stfn stfu stnn stnr stns stob stof ston stoo stor stos stot stou strc strn stro strs stru stsf stss sttc sttr stub stuc stuf stun stur stus stut sub- subb subo subs suc- succ sucr sucs suf- sufc suff sufr sufs sufu sun- sunb sunn suno suns sunt sunu suor suos sur- surc surf surn suro surr surs surt suru sus- suso suss sust susu suto sutu suus tbbs tbcb tbcc tbnf tbrb tbst tcbs tccc tccu tcfc tcnn tcon tcos tctc tcts tfcu tfot tfrs tfss tftc tnbc tncc tnfc tnts tnut tobo tobs tobt tobu toco toff tofo toft tofu tonb tonn tono tons tonu toof toon toor toos toot torc torf torn toro torr tors tort toru tosb tosc toso toss tost tosu totc toto totr tots tott toun tour tous tout trcc trfc trfr trno troc tron troo tros trot trou trst trtc trtr trub truc trun trus trut truu tsbc tscc tsfc tsob tsos tsou tssf tssr tsst tstc tsts tsun ttbb ttcn ttfc ttff ttfn tton ttss tttt tubb tubo tubr tubs tubu tucc tuco tufc tuff tufo tuft tufu tunb tunc tunn tuno tuns tunu tuor tuos turb turc turf turn turo turr turs turt turu tusc tuss tust tuto tuts tutt tutu tuuo ubbo uboc ubon ubos ubtf ucbc ucfb ucon ucos ucrc ucsb ucsc ucsf ucst ucsu ucut ufcu ufos uncc uncf unco uncs unct unno unns unon unos unrf unro unrs uns- unsc unso unst untb unto unts unus unut uocc uofo uor- urbs urff urft urns uro- uroo urso urss ursu urts urun urur urus urut usbc usbr usbs uscc uscf usco uscs usfc usfs usnc usno usnr usnu usoc usos ussb ussc ussf ussr usss usst ussu ustb ustc usto usts usun usus utfo utor utsc utto uttu uuno uuoc uutf uuuu