iiii iiio iiis iioi iioo iiop iios iirs iisi iisp iisr ioii ioio iooi iooo ioos iops iori iors ioso ipop ipos ippo ippr ipri ipsi ipso ipsp ipss ipvs iri- irio irip iris irop irov irps irri irrs irsp irvs isis iso- isop isor isos ispr isps isri isrp issi isso issp issr isss ivor ivrs oiii oios oooo ooos oops oosi opii opio opis opo- opor opos oppi oppo opps opsi ori- orio oris oro- oror oros orpi orps orri orro orrs orsi orso orvr orvs osii osip osis osoi osoo osor osos osov osro ossi osso ovi- ovis ovo- ovoo ovpp piip pipi pipo pipp pips piri piro pirr pirs pisi piso piss pivo poio pois poop poor poos pop- popi popo popp pops pori poro porr pors posi poso poss povo povs ppos pppo pppp ppps ppss pri- prii pris priv pro- proo prop pros prov prps prri prrs prsi prso prss prsv psip psis psoi psos psov pspi pspp pspr psps psrp psso riis rios ripi ripp ripr rips riri rirs risi riso risp riss rivo rivp rivs roio roir rois rooi roop roor roos ropo rops rori roro rosi roso rosp ross rovi rovo rovs rpii rpos rpps rrrr rrsp rsis rsos rspo rsps rsvp rvsp s-ii s-iv s-os siop sior sios sipi sipo sipp sips siri siro sirp sirr sirs sisi siss sivi soir sois soop soor soos sopi sopo sopp sops sori soro sorr sors sosi soso soss sosv sovo sovs spio spip spir spis spiv spoo spop spor spos spps spri spro sprs spso spsp spss sris sros srps srsp ssis ssop sspo ssps ssri ssrs sssi ssss ssvp svir svor viii vios vipr vips viri viro virr visi viso visp viss vivi vivo voio voip voir vois voor vor- vori voro vors vosi voso voss vpro vrio vris vrsi vsip vsop vsrp vvvv