d-ix dddd ddss ddts dfds dfdt dfts didi dids dif- diff difs diii diis dis- disd disi diss dist diti dits ditt dixi dsif dssi dsst dsts dtss dttx dtxt dxds dxfx dxif dxii dxix dxss dxts dxxx fdst fdti ffff ffii ffss fftf fidf fids fiff fifi fift fiii fisd fisi fiss fist fiti fits fitt fixt fixx fsfi fsix fssf ftdi ftii fxdd 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 ixxi s-ii sdds sdif sdsf sdss sdxf sfss sfts sidd sidi sids siff sift siit sisd sisi siss sist sit- sitd siti sits sitt sixt sixx ssdd ssdf ssid ssis ssit sssf sssi ssss sstd ssts stds stid stif stis stit stix stsf stsi stss sttd tdff tdis tdss tfsd tfsi tfss tidd tids tiff tift tiit tisi tiss tist titi tits titt tixt tsid tsis tsix tssf tssi tsst tsts ttff ttss tttt txii x-fi xdxf xidi xiii xisi xist xixi xxii xxix xxxi xxxx