bbbb bbpr bkpr bobb bobo boko boob book boop boor bopp bor- bork boro borr brkb brob brok broo bror brrr kbbb kbbk kbbo kbbr kbkb kbkk kbko kbkr kbob kbok kboo kbpk kbpo kbpr kbrb kbrk kbro kkbb kkbo kkbr kkkk kkob kkoo kkor kkpk kkrb kkrk kkro kkrr kobb kobk kobo kobr kokb kokk koko kokp kokr koob kook kooo koop koor kopb kopp kopr korb kork koro korr kpbb kpbr kpkk kpkr kpob kpok kpoo kpop kppk kppo kppp kppr kprb kprk kpro kprp kprr krbb krbk krbr krkk krko krkr krob krok kroo krop kror krpr krrb krrk krro krrr obbo obkb obok obor obro okko okok okor okpo okro oooo opo- opor oppo orbb orbo orko oro- orok oror orro pbpk pobo poko pook poop poor pop- popo popp porb pork poro porr pppo pppp pro- prob proo prop rbbb rbbr rob- robb robo rokk roko rokr roob rook roop roor ropo rork roro rpob rrrr