bbbb bbbs bobb bobo bobs boko boks boob book boor boos bor- bork boro borr bors bosk boso boss brkb brob brok broo bror bros brrr brrs brsb brsr bsos k-os kbbb kbbk kbbo kbbr kbbs kbkb kbkk kbko kbkr kbob kbok kboo kbos kbrb kbrk kbro kbsb kbsk kbso kbsr kbss kkbb kkbo kkbr kkbs kkkk kkob kkoo kkor kkrb kkrk kkro kkrr kkrs kksr kkss kobb kobk kobo kobr kobs kokb kokk koko kokr koks koob kook kooo koor koos korb kork koro korr kors kos- kosb koso kosr koss krbb krbk krbr krkk krko krkr krks krob krok kroo kror kros krrb krrk krro krrr krrs krsk krsr krss ksbr ksbs kskb kskk ksko kskr ksks ksob ksok ksoo ksor ksos ksrb ksro ksrr ksrs ksso kssr ksss obbo obkb obok obor obos obro obsr obss okko okok okor okro okso oooo ooos orbb orbo orbs orko oro- orok oror oros orro orrs orsk orso osoo osor osos osro ossb osso rbbb rbbr rbbs rbss rkos rkss rob- robb robo robs rokk roko rokr roks roob rook roor roos rork roro roso ross rrrr rsos s-os sbbs sbor sbrk skor skss sobo sobr sobs sokk soko sook soor soos sorb soro sorr sors soso soss sros ssbr ssrs sssb ssss