bbbb bbbs bbpr bibb bibi bibo bibs biis bio- bioi bios bipp bips birb biri biro birr birs bis- biso bisp biss bobb bobi bobo bobs boi- boii bois boob boop boor boos bopp bops bor- bori boro borr bors bosi boso boss brio bris brob broo bror bros brrr brrs brsb brsr bsos bspp bspr ibis ibos ibri ibro ibss iiii iiio iiis iioi iioo iiop iios iirs iisi iisp iisr iobi ioii ioio iooi iooo ioos iops iori iors ioso ipop ipos ippo ippr ipri ipsi ipso ipsp ipss irbp iri- irio irip iris irob irop irps irri irrs irsp isis iso- isop isor isos ispr isps isri isrp issi isso issp issr isss obbo obis oboi obor obos obri obro obsr obss oiii oios oobi oooo ooos oops oosi opii opio opis opo- opor opos oppi oppo opps opsi orbb orbi orbo orbs ori- orio oris oro- oror oros orpi orps orri orro orrs orsi orso osbp osii osip osis osoi osoo osor osos osro ossb ossi osso pbrs pbsp pibb pibi piip piob pipi pipo pipp pips piri piro pirr pirs pisi piso piss pobo pobs poio pois poop poor poos pop- popi popo popp pops porb pori poro porr pors posb posi poso poss ppib ppos pppo pppp ppps ppss prbs pri- prii pris pro- prob proo prop pros prps prri prrs prsi prso prss psbr psip psis psoi psos pspi pspp pspr psps psrp psso rbbb rbbr rbbs rbis rbsp rbss rib- ribo ribs riis rios ripi ripp ripr rips riri rirs risi riso risp riss rob- robb robi robo robs roio roir rois roob rooi roop roor roos ropo rops rori roro rosi roso rosp ross rpii rpob rpos rpps rrrr rrsp rsbi rsis rsos rspb rspo rsps s-ib s-ii s-os sbbs sbor sbsi sbsp sibi sibo sibs siop sior sios sipi sipo sipp sips siri siro sirp sirr sirs sisi siss sobo sobp sobr sobs soir sois soop soor soos sopi sopo sopp sops sorb sori soro sorr sors sosi soso soss spib spio spip spir spis spoo spop spor spos spps spri spro sprs spso spsp spss srib sris sros srps srsp ssbr ssis ssop sspo ssps ssri ssrs sssb sssi ssss