bbbb bbbs bblb bbls bibb bibi bibl bibs biis bili bill bils bilt bis- bisl biss bist bits bitt bitx bixi blbt blis blit blix blls blss blst blts bsix bsts btss bttb ibis ibss ibtb ibtl ibts iiii iiis iiit iisi iist iitt ilbx ilis ilit ill- illi ills illt ilts ilxx isbl isbt isbx isil isis isit isls issi isss isti ists itbs itil itis itll itsi ixil ixxi libs libx liii liis lilb lili lill lils lilt lisi liss list litb liti litl lits litt lixi lixt llbs llll lsts ltbl ltib ltsi lxii lxis lxxi lxxx s-ib s-ii sbbs sbsi sbst sibi sibs siit sil- sili sill sils silt sisi siss sist sit- siti sits sitt sixt sixx sl-i slib slit slst slts ssis ssit sslt sssb sssi ssss sstb sstl ssts stbs stib stil stis stit stix stlt stsi stss sxbl tbbs tbil tbit tbst tibi tibs tiit till tils tilt tisb tisi tiss tist titi tits titt tixt tlli tltx tsis tsix tssi tsst tsts ttbb ttss tttt txii xiii xil- xili xill xisi xist xixi xlib xlii xlix xsil xslt xtbs xxii xxix xxxi xxxx