iiii iiio iiis iiit iioi iioo iios iirs iisi iisr iist iitr iitt ioii ioio ioit iooi iooo ioos iori iors ioso ioto iri- irio iris irri irrs irti irts isis isit iso- isor isos isri issi isso issr isss isti isto istr ists itis itoi itoo itor itos itri itrs itsi itso itto oiii oios oirt oist oiti oooo ooos oort oosi oost oots ori- orio oris orit oro- oror oros orot orri orro orrs orsi orso orto orts osii osis osoi osoo osor osos osro ossi osso osti ostr osts otis otit oto- otoo otor otos otro otrs otso otti otto otts riis rios riot riri rirs risi riso riss rist riti rito rits ritt roio roir rois roit rooi roor roos root rori roro rort rosi roso ross rost roti roto rotr rots rott rrrr rsis rsos rsts rtss rtts s-ii s-os siit sior sios siot siri siro sirr sirs sirt sisi siss sist sit- siti sito sits sitt soir sois soit soor soos soot sori soro sorr sors sort sosi soso soss sost soto sots sris sros srtr ssis ssit ssot ssri ssrs sssi ssss ssts stio stir stis stit stoo stor stos stot stri stro strs stsi stss sttr tiit tios tiri tiro tirr tirs tisi tiso tiss tist titi tito tits titt tois toit toor toos toot tori toro torr tors tort tosi toso toss tost toti toto totr tots tott tri- trio tris trit troi troo tros trot trsi trst trtr tsis tsoi tsos tssi tssr tsst tsts ttss tttt