iiii iiio iiis iioi iioo iiop iios iisi iisp ioii ioio iooi iooo ioos iops ioso ipop ipos ippo ipsi ipso ipsp ipss isis iso- isop isos isps issi isso issp isss oiii oios oooo ooos oops oosi opii opio opis opo- opos oppi oppo opps opsi osii osip osis osoi osoo osos ossi osso piip pipi pipo pipp pips pisi piso piss poio pois poop poos pop- popi popo popp pops posi poso poss ppos pppo pppp ppps ppss psip psis psoi psos pspi pspp psps psso s-ii s-os siop sios sipi sipo sipp sips sisi siss sois soop soos sopi sopo sopp sops sosi soso soss spio spip spis spoo spop spos spps spso spsp spss ssis ssop sspo ssps sssi ssss