bbbb bbbs bblb bbls bibb bibi bibl bibs biis bili bill bils bilu bis- bisl biss bisu blis blls blss blub blus bubb bubi bubs bubu buis buiu bulb buli bull buls bulu busi buss busu buus ibis ibss ibus iiii iiis iisi iisu ilis ill- illi ills ilus isbl isil isis isls issi isss issu isus iuiu iuss libs libu liii liis lilb lili lill lils lilu lisi liss lisu lius llbs llll lsbu lubs luis luli lull lulu lusi luss s-ib s-ii sbbs sbsi sbus sibi sibs sibu sil- sili sill sils silu sisi siss sisu siui sius sl-i slib slsu slub ssis sssb sssi ssss sub- subb subi subl subs suis sul- suli sull sulu sus- susi suss susu suus ubbi ubii ubis ubli ubls ulli ulul ulus usbl usbs usis uslu ussb usss ussu usui usul usus uulu uusi uuuu