rac- raca racc race racs racu raec raep raer raes rapa rapc rape rapp raps rara rarb rare rars rasa rasc rase rasp rass rasu raua raub rauc raue raup raus rbbb rbbr rbbs rbsp rbss rcac rcas rcbc rccb rccc rccs rcep rcps rcsa rcsc rcss rea- reac reae reap rear reas reau reba rebb rebe rebs rebu reca recc rece recp recr recs recu reeb reep rees repe repp repr reps repu rera rere rers reru resa rese resp ress reue reup reus reuu rpca rpcs rpps rras rrrr rrsp rsaa rscc rscs rsee rspb rsps rsre rssa rsua ruas ruba rubb rube rubp rubs rubu ruca ruce ruer rues rupa rupe rupp rura rurc rure rurp rurs ruru rusa ruse russ rusu sa-c saab saac saae saap saar saas saba sabb sabc sabe sabr sabs sabu saca sacc sace sacr sacs sacu saeb saer saes sapa sape sapp saps sara sarc sare sarp sarr sars saru sasa sasc sase sass saua sauc saue saup saur saus sbaa sbac sbar sbas sbbs sbca sbcc sbcs sber sbsa sbse sbsp sbus scaa scab scac scap scar scas scba sccc scce sccp sccs scea scec scee scep scer scpa scpb scpe scps scr- scra scrc scre scrs scsa scsc scsr scsu scua scub scup scur se-c se-e se-s se-u seaa seab seac seap sear seas seau seba sebe sebs sec- seca secc sece secr secs secu seea seeb seec seep seer sees seeu sepa sepe sepp sepr seps sepu sera serb serc sere serp serr sers seru sesa sesc sese sess seur sp-a spac spae spap spar spas spau spca spcc spcs spea speb spec spee sper spes spps sprs spsa spse spsp spss spue spur spus sras srbc srcc sreb srec sres srpc srps srsp srub ssaa ssab ssac ssap ssas ssau ssbr ssca sscc ssce sscp sscs ssec ssee ssep sses sspa sspc sspe ssps ssra ssrc ssrs sssa sssb sssc ssss suar suas sub- suba subb subs suc- succ sucr sucs suee suer sues sueu sup- supa supe supp supr sups sur- sura surc sure surp surr surs suru sus- susa suse susp suss susu suus u-rp uabc uaca uaes uarc uars uaru uasa uasp uaua ubac ubar ubba ubbe uber ubpc ubra ucar ucas ucbc ucca uccp ucea uces ucpa ucpb ucrc ucsa ucsb ucsc ucsu ucua ueba uers uess upac upar upas upbe upca upcs uppa uppc uppe uppp uppu upra upsa upsc upse upup urac urap uras urau urba urbe urbs urca ure- urea ures urra urre ursa urse urss ursu urup urur urus us-a usaa usac usap usar usas usba usbc usbe usbr usbs usca uscc usce uscs usea usee user uses uspa uspc uspp usps usra ussa ussb ussc usse ussr usss ussu usua usus uucp uuuu