cccc cccp ccoc ccpp ccpr ccrc ccrp ckck ckco ckoc ckoo ckor ckpc ckpr ckrc cock coco cocp cok- coko cook coop copo copp copr cor- corc cork coro corp corr crcc crcr crkc crkp croc crok croo crop cror crpc kccc kcck kccr kckc kckk kcko kckr kcor kcpc kcpo kcpr kcrc kcro kcrp kcrr kkck kkco kkcr kkkk kkoo kkor kkpc kkpk kkrc kkrk kkro kkrr kock kocp kokc kokk koko kokp kokr kooc kook kooo koop koor kopp kopr korc kork koro korr kpcc kpcr kpkk kpkr kpoc kpok kpoo kpop kppc kppk kppo kppp kppr kprc kprk kpro kprp kprr krcc krco krkc krkk krko krkr kroc krok kroo krop kror krpr krrc krrk krro krrr occc ocpp ocro ocrr okko okok okor okpo okro oocr oooo opo- opor oppo orco orko oro- orok oror orpc orro pccc pcpp pcrc pock poco poko pook poop poor pop- popc popo popp porc pork poro porr ppcc pppo pppp pprc prcc prcp pro- proc proo prop rccc rcpo rocc rock roco rokk roko rokr rook roop roor ropo rorc rork roro rrrr