bbbb bbbs bobb bobo bobs boko boks boob book boor boos bor- bork boro borr bors bosk boso boss bovo brkb brob brok broo bror bros brrr brrs brsb brsr bsos k-os kbbb kbbk kbbo kbbr kbbs kbkb kbkk kbko kbkr kbkv kbob kbok kboo kbos kbov kbrb kbrk kbro kbrv kbsb kbsk kbso kbsr kbss kbsv kbvb kbvo kbvr kkbb kkbo kkbr kkbs kkkk kkob kkoo kkor kkov kkrb kkrk kkro kkrr kkrs kkrv kksr kkss kkvr kkvv kobb kobk kobo kobr kobs kokb kokk koko kokr koks koob kook kooo koor koos koov korb kork koro korr kors korv kos- kosb koso kosr koss kovk kovo kovr krbb krbk krbr krkk krko krkr krks krkv krob krok kroo kror kros krov krrb krrk krro krrr krrs krsk krsr krss krsv krvb krvk krvo krvr krvs krvv ksbr ksbs ksbv kskb kskk ksko kskr ksks ksob ksok ksoo ksor ksos ksrb ksro ksrr ksrs ksrv ksso kssr ksss ksvr kvbr kvob kvok kvoo kvor kvov kvro kvrr kvrv kvso kvsr kvss kvsv kvvr kvvs kvvv obbo obkb obok obor obos obro obsr obss obvs okko okok okor okro okso oooo ooos orbb orbo orbs orko oro- orok oror oros orro orrs orsk orso orvr orvs osoo osor osos osov osro ossb osso ovo- ovoo rbbb rbbr rbbs rbss rkos rkss rksv rob- robb robo robs rokk roko rokr roks roob rook roor roos rork roro roso ross rovo rovs rrrr rsos s-os sbbs sbor sbrk skor skov skss sobo sobr sobs sokk soko sook soor soos sorb soro sorr sors soso soss sosv sovo sovs sros ssbr ssrs sssb ssss svor vkor voks voor vor- voro vors voso voss vovk vvob vvsb vvvv