bbb bbf bbi bbl bbs bbt bfb bff bfi bfl bfs bft bi- bib bif bii bil bis bit blb blf bli bll bls blt bsb bsf bsi bsl bss bst btb btf bti btl bts btt fbb fbf fbi fbl fbs fbt fff ffi ffl ffs fft fib fif fii fil fis fit flb flf fli fll fls flt fsb fsf fsi fsl fss fst ftb ftf fti ftl fts ftt i-f ibb ibf ibi ibl ibs ibt ifb iff ifi ifl ifs ift iib iif iii iil iis iit il- ilb ilf ili ill ils ilt is- isb isf isi isl iss ist itb itf iti itl its itt lbb lbf lbi lbl lbs lbt lfb lff lfi lfl lfs lft lib lif lii lil lis lit llb llf lli lll lls llt lsb lsf lsi lsl lss lst ltb ltf lti ltl lts ltt sbb sbf sbi sbl sbs sbt sfb sff sfi sfl sfs sft sib sif sii sil sis sit slb slf sli sll sls slt ss- ssb ssf ssi ssl sss sst stb stf sti stl sts stt tbb tbf tbi tbl tbs tbt tfb tff tfi tfl tfs tft tib tif tii til tis tit tlf tli tll tls tlt tsb tsf tsi tsl tss tst ttb ttf tti ttl tts ttt