bbbb bbbs bblb bbls bffl bffs bfsi bfsr bibb bibi bibl bibs biff bifi biis bili bill bils birb biri birl birr birs bis- bisl biss blir blis blls blss bril bris brls brrr brrs brsb brsr bsff bsfs fbis fbrs ffff ffii ffrr ffss fibs fiff fifi fiii fiil fili fill fils firs fisi fiss flii flis frib fril fris frsb fsfi fssf ibfi ibis ibri ibsf ibss ifbb ifil ifis ifrb ifrf ifri ifsb iiii iiis iirs iisi iisr ilir ilis ill- illi ills iri- iril iris irlb irri irrs irsf isbl isil isis isls isri issf issi issr isss lblr lbrs libr libs liff lifl liii liir liis lilb lili lill lils liri lirl lirr lirs lisi liss llbs llll lrif lrrr ls-r lssr rbbb rbbr rbbs rbis rbsl rbss rffl rib- ribs riff rifs riif riis rill riri rirs risi riss rlif rlls rrif rrrr rsbi rsis rssl s-ib s-ii sbbs sbsi sfls sfss sibi sibs siff sifl sifr sil- silf sili sill sils sirf siri sirr sirs sisi siss sl-i slib slir slrs srfi srib sris ssbr ssfl ssis ssri ssrl ssrs sssb sssf sssi ssss