dddd ddss ddts dfds dfdt dfts didi dids dif- diff difs diii diis dis- disd disi diss dist diti dits ditt dsif dssi dsst dsts dtss fdst fdti ffff ffii ffss fftf fidf fids fiff fifi fift fiii fisd fisi fiss fist fiti fits fitt fsfi fssf ftdi ftii idid idis idsf idss idts ifid ifis ifit iiii iiis iiit iisd iisi iist iitt isds isis isit issf issi isss istd isti ists itif itis itsf itsi ittf s-ii sdds sdif sdsf sdss sfss sfts sidd sidi sids siff sift siit sisd sisi siss sist sit- sitd siti sits sitt ssdd ssdf ssid ssis ssit sssf sssi ssss sstd ssts stds stid stif stis stit stsf stsi stss sttd tdff tdis tdss tfsd tfsi tfss tidd tids tiff tift tiit tisi tiss tist titi tits titt tsid tsis tssf tssi tsst tsts ttff ttss tttt