bbbb bbbs bbpr bobb bobo bobs boob boop boor boos bopp bops bor- boro borr bors boso boss brob broo bror bros brrr brrs brsb brsr bsos bspp bspr obbo obor obos obro obsr obss oooo ooos oops opo- opor opos oppo opps orbb orbo orbs oro- oror oros orps orro orrs orso osbp osoo osor osos osro ossb osso pbrs pbsp pobo pobs poop poor poos pop- popo popp pops porb poro porr pors posb poso poss ppos pppo pppp ppps ppss prbs pro- prob proo prop pros prps prrs prso prss psbr psos pspp pspr psps psrp psso rbbb rbbr rbbs rbsp rbss rob- robb robo robs roob roop roor roos ropo rops roro roso rosp ross rpob rpos rpps rrrr rrsp rsos rspb rspo rsps s-os sbbs sbor sbsp sobo sobp sobr sobs soop soor soos sopo sopp sops sorb soro sorr sors soso soss spoo spop spor spos spps spro sprs spso spsp spss sros srps srsp ssbr ssop sspo ssps ssrs sssb ssss