bbbb bbdd bbdo bbpr bd-r bdii bibb bibi bibo bidi bido bidr bio- bioi bipp birb bird biri biro birr bobb bobi bobo bodb bodi bodo boi- boid boii boob bood boop boor bopp bor- bord bori boro borr bprd brdo brid brio brob brod broo bror brrr d-bo dbpd dddd ddpo dibb dibo dibp didi dido diii diop dior dipo dipp dird dirr dobb dobi dod- dodd dodi dodo doid doob dood doop door dopo dopp dopr dord dori doro dorp dorr drib drip drob drod drop ibdo ibid ibrd ibri ibro iddo idid idio idir idro iiii iiio iioi iioo iiop iobi iod- iodd iodo ioii ioio iooi iooo iori ipdi ipid ipod ipop ippo ippr ipri irbp irdo irdp iri- irid irio irip irob irod irop irri obbo obid oboi obor obri obro odbo oddd oddi odio odir odoo odop odor odrp oido oiii oobi oodi ooid oooo oord opii opio opo- opor oppi oppo orbb orbi orbo ordo ori- orid orio oro- oror orpi orri orro pdpr pibb pibi pido piip piob pipi pipo pipp piri piro pirr pobo pod- podd podi podo poid poio pood poop poor pop- popi popo popp porb pori poro porr ppib ppid ppod pppd pppo pppp pri- prid prii pro- prob prod proo prop prpd prrd prri rbbb rbbr rdbp rdio rib- ribo ridd ridi rido ripd ripi ripp ripr riri rob- robb robi robo rodd rodi rodo roid roio roir roob rood rooi roop roor ropo rori roro rpdp rpii rpob rrrr