bbbb bbbs bibb bibi bibo bibs biis biko bio- bioi bios birb biri birk biro birr birs bis- bisk biso biss bobb bobi bobo bobs boi- boii bois boki boko boks boob book boor boos bor- bori bork boro borr bors bosi bosk boso boss brik brio bris brkb brob brok broo bror bros brrr brrs brsb brsr bsos ibis ibos ibri ibro ibss iiii iiio iiis iioi iioo iios iirs iisi iisr ikki ikko ikoo ikri iobi ioii ioio ioko iooi iooo ioos iori iors ioso iri- irio iris irki irks irob irri irrs isis isko iso- isok isor isos isri issi isso issr isss k-os kbbb kbbi kbbk kbbo kbbr kbbs kbib kbik kbio kbis kbkb kbkk kbko kbkr kbob kboi kbok kboo kbos kbrb kbri kbrk kbro kbsb kbsi kbsk kbso kbsr kbss kibb kibi kibo kibr kibs kiii kiik kiis kiki kikk kiko kikr kioi kiok kioo kirb kiri kirk kiro kirr kirs kisi kisk kiso kisr kiss kkbb kkbi kkbo kkbr kkbs kkik kkkk kkob kkoo kkor kkrb kkrk kkro kkrr kkrs kksi kksr kkss kobb kobi kobk kobo kobr kobs koii koir kokb koki kokk koko kokr koks koob kooi kook kooo koor koos korb kori kork koro korr kors kos- kosb kosi koso kosr koss krbb krbi krbk krbr krib krik krio kris krki krkk krko krkr krks krob kroi krok kroo kror kros krrb krri krrk krro krrr krrs krsk krsr krss ksbi ksbr ksbs ksib ksii ksik ksir ksis kskb kskk ksko kskr ksks ksob ksoi ksok ksoo ksor ksos ksrb ksro ksrr ksrs kssi ksso kssr ksss obbo obis obkb oboi obok obor obos obri obro obsr obss oiii oiko oiks oios okir okko okok okor okro oksi okso oobi oooo ooos oosi orbb orbi orbo orbs ori- orio oris orko oro- orok oror oros orri orro orrs orsi orsk orso osii osik osis oski osoi osoo osor osos osro ossb ossi osso rbbb rbbr rbbs rbis rbss rib- ribo ribs riis riki rikk rios riri rirs risi risk riso riss rkos rkss rob- robb robi robo robs roik roio roir rois roki rokk roko rokr roks roob rooi rook roor roos rori rork roro rosi roso ross rrrr rsbi rsis rsos s-ib s-ii s-os sbbs sbor sbrk sbsi sibi sibo sibs siik siki siko sikr siks sior sios siri sirk siro sirr sirs sisi sisk siss skik skio skir skis skor skss sobo sobr sobs soik soir sois soki sokk soko sook soor soos sorb sori soro sorr sors sosi soso soss srib sris sros ssbr ssis ssri ssrs sssb sssi ssss