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 iri- irio irip iris irop irps irri irrs irsp isis iso- isop isor isos ispr isps isri isrp issi isso issp issr isss 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 osii osip osis osoi osoo osor osos osro ossi osso piip pipi pipo pipp pips piri piro pirr pirs pisi piso piss poio pois poop poor poos pop- popi popo popp pops pori poro porr pors posi poso poss ppos pppo pppp ppps ppss pri- prii pris pro- proo prop pros prps prri prrs prsi prso prss psip psis psoi psos pspi pspp pspr psps psrp psso riis rios ripi ripp ripr rips riri rirs risi riso risp riss roio roir rois rooi roop roor roos ropo rops rori roro rosi roso rosp ross rpii rpos rpps rrrr rrsp rsis rsos rspo rsps s-ii s-os siop sior sios sipi sipo sipp sips siri siro sirp sirr sirs sisi siss soir sois soop soor soos sopi sopo sopp sops sori soro sorr sors sosi soso soss spio spip spir spis spoo spop spor spos spps spri spro sprs spso spsp spss sris sros srps srsp ssis ssop sspo ssps ssri ssrs sssi ssss