bbb bbf bbi bbs bbt bfb bff bfi bfs bft bi- bib bif bii bis bit bsb bsf bsi bss bst btb btf bti bts btt fbb fbf fbi fbs fbt fff ffi ffs fft fib fif fii fis fit fsb fsf fsi fss fst ftb ftf fti fts ftt i-f ibb ibf ibi ibs ibt ifb iff ifi ifs ift iib iif iii iis iit is- isb isf isi iss ist itb itf iti its itt sbb sbf sbi sbs sbt sfb sff sfi sfs sft sib sif sii sis sit ss- ssb ssf ssi sss sst stb stf sti sts stt tbb tbf tbi tbs tbt tfb tff tfi tfs tft tib tif tii tis tit tsb tsf tsi tss tst ttb ttf tti tts ttt