bbbb bblb bibb bibi bibl bili bill bilu birb biri birl birr biru bivi bivl blir blub blur bril brrr bruv brvi bubb bubi bubu buir buiu bulb buli bull bulu bur- burb buri burl burr buru ibri iiii ilir ill- illi iluv iri- iril irlb irri irul iuiu ivbv lblr libr libu liii liir liiv lilb lili lill lilu liri lirl lirr liru livi llll lrrr luli lull lulu luri lurv lvii lviv lvrr rbbb rbbr rib- ribu rill rilu riri rrrr rubb rubi rubu rull ruri ruru ruvi ruvu ubbi ubii ubir ubli uirr ulli ullr ulul ulvi urbi urib uriu urri urur uulu uuri uuuu uv-b uvri uvvu viii vili vill vilu virb viri virl virr viru vivi vlli vrbl vril vuir vull vurb vvvv