ffff ffii ffss fftf fiff fifi fifo fift fiii fios fisi fiss fist fiti fits fitt fofo fois foof foos foot fosi foso foss fost foti foto fots fott foty foys foyt fsfi fsfo fssf ftfy ftii ftos fyfi fyti iffy ifis ifit ifso ifto ifyo iiii iiio iiis iiit iioi iioo iios iisi iist iitt ioii ioio ioit ioof iooi iooo ioos ioso iotf ioto isis isit iso- isof isos issf issi isso isss issy isti isto ists isty isys itif itis itof itoi itoo itos itsf itsi itso itsy ittf itto itty iyos off- offo offs offy ofit ofst oiii oios oist oiti ooff oofs oofy oooo ooos oosi oost oots ooty osii osis osoi osoo osos ossi osso ossy osti osts osyt otif otis otit oto- otof otoo otos otoy otso otti otto otts oyss oyst s-ii s-os sfio sfos sfss sfts siff sifo sift sify siit sios siot sisi siss sist sisy sit- siti sito sits sitt sity siyi sofi sofo soft soif sois soit soof soos soot sooy sosi soso soss sost soto sots soyo soys soyt ssis ssit ssot sssf sssi ssss ssts stif stio stis stit stof stoo stos stot stoy stsf stsi stss styf stys syff syfy syis syso syss syst sytt tfot tfsi tfss tiff tifo tift tiit tios tisi tiso tiss tist titi tito tits titt tiyi tiyo to-y toff tofi tofo toft tois toit toof toos toot tosi toso toss tost tosy toti toto tots tott toty toyo toys toyt tsis tsoi tsos tsoy tssf tssi tsst tsts tsys ttff ttoy ttss tttt ttys tyff tyft tyss tyst tyti tyto tytt tyty yiff yift yiss yist yiti yoff yoit yoof yoot yosi yoso yost yott yoyo ysii yyff yyyy