bbbb bbpr bbrc bcbc bcbp bccc bcor bcpp bcru bcuc bcup bobb bobo bobu boco bocu boob booc boop boor bopp bor- boro borr boru boup bour bpcp bprc brcb brob broc broo bror brou brrr bruc brup bubb bubo bubu bucc buco bucu bupc bur- burb buro burp burr buru c-bo cbbc cbcc cbcp cbcr cbcu cbpc cbpp ccbc cccb cccc cccp cccu ccob ccoc ccpp ccpr ccrc ccrp ccuc ccup cobb cobo cobu coco cocp cocu coob coop copo copp copr cor- corb corc coro corp corr coub coup cour cpbc cpcu crbc crbu crcc crcr crob croc croo crop cror crpc crub crup cub- cubb cucc cupo cupp cupr curb curo curr obbo obor obro ocbc occc ocpp ocro ocrr ocur oocr oooo opo- opor oppo orbb orbo orbu orco oro- oror orpc orro orub orup oucc our- ouro ouu- pbcc pboc pcbc pccc pcpb pcpp pcrc pobo poco poop poor pop- popc popo popp porb porc poro porr poup pour ppcc pppo pppp pprc ppru ppur prbc prcc prcp pro- prob proc proo prop prou pruu pubu pupu pur- purb puro purp purr puru puuc rbbb rbbr rcbc rcbo rccb rccc rcpo rob- robb robo robu rocc roco roob roop roor ropo rorc roro roru roub roup rpob rrrr rubb rubp rubu rupp rurc ruro rurp ruru u-rp ubbo uboc ubpc ucbc uccp ucpb ucrc uocc uor- upor uppc uppp uppu upup uro- uroo urpo urup urur uucp uuoc uuuu