bbbb bbbs bbrc bcbc bcbs bccc bccs bcrs bcru bcsc bcss bctc bcts bcuc brcb brrr brrs brsb brsr brst brtc bruc brus brut bscs bssc bsts btcc btcs btrc btrt btss bttb btus bubb bubs bubu bucc bucs bucu bur- burb burr burs burt buru busc buss bust busu but- buts butt buus cbbc cbbs cbcc cbcr cbcs cbct cbcu cbrt cbsc cbtc cbus ccbc cccb cccc cccs cccu ccrc ccrs ccrt ccss ccst cctb cctc cctt ccuc ccus ccut crbc crbu crcc crcr crrt crss crst crtc crts crub crus crut cscb cscc cscr cscs csrc csrs cssr cstc cstr csts csur csus ctbs ctrc ctrs ctsc ctss ctsu ctts cub- cubb cubs cucc curb curr curs curt cusb cuss cust cusu cut- cutc cuts cutt rbbb rbbr rbbs rbss rbst rcbc rccb rccc rccs rcsc rcss rctc rcts rrrr rscc rscs rsts rstu rtcc rtss rtts rubb rubs rubu ruct rurc rurs ruru russ rust rusu ruts rutt rutu sbbs sbcc sbcs sbct sbst sbtc sbus sccc sccs scct scr- scrc scrs scsc scsr scst scsu sctc sctr scts scub scur scut srbc srcc srct srtr srub ssbr sscc sscs ssrc ssrs sssb sssc ssss sstb sstc ssts stbc stbs stcc stcs stcu strc strs stru stss sttc sttr stub stuc stur stus stut sub- subb subs suc- succ sucr sucs sur- surc surr surs surt suru sus- suss sust susu sutu suus tbbs tbcb tbcc tbrb tbst tcbs tccc tccu tctc tcts trcc trst trtc trtr trub truc trus trut truu tsbc tscc tssr tsst tstc tsts ttbb ttss tttt tubb tubr tubs tubu tucc turb turc turr turs turt turu tusc tuss tust tuts tutt tutu ucbc ucrc ucsb ucsc ucst ucsu ucut urbs urss ursu urts urur urus urut usbc usbr usbs uscc uscs ussb ussc ussr usss usst ussu ustb ustc usts usus utsc uttu uuuu