bbb bbf bbi bbo bbs bbt bfb bff bfi bfo bfs bft bi- bib bif bii bio bis bit bob bof boi boo bos bot bsb bsf bsi bso bss bst btb btf bti bto bts btt fbb fbf fbi fbo fbs fbt fff ffi ffo ffs fft fib fif fii fis fit fob fof foi foo fos fot fsb fsf fsi fso fss fst ftb ftf fti fto fts ftt i-f ibb ibf ibi ibo ibs ibt ifb iff ifi ifo ifs ift iib iif iii iio iis iit io- iob iof ioi ioo ios iot is- isb isf isi iso iss ist itb itf iti ito its itt o-i ob- obb obf obi obo obs obt of- ofb off ofi ofo ofs oft oib oif oii oio ois oit oo- oob oof ooi ooo oos oot os- osb osf osi oso oss ost ot- otb otf oti oto ots ott sbb sbf sbi sbo sbs sbt sfb sff sfi sfo sfs sft sib sif sii sio sis sit sob sof soi soo sos sot ss- ssb ssf ssi sso sss sst stb stf sti sto sts stt tbb tbf tbi tbo tbs tbt tfb tff tfi tfo tfs tft tib tif tii tio tis tit to- tob tof toi too tos tot tsb tsf tsi tso tss tst ttb ttf tti tto tts ttt