bbb bbe bbf bbo bbs bbt bbx be- beb bee bef beo bes bet bex bfb bfe bff bfo bfs bft bfx bob boe bof boo bos bot box bsb bse bsf bso bss bst bsx btb bte btf bto bts btt btx bxb bxo bxx ebb ebe ebf ebo ebs ebt ebx eeb eee eef eeo ees eet eex ef- efb efe eff efo efs eft efx eo- eob eoe eof eoo eos eot es- esb ese esf eso ess est esx etb ete etf eto ets ett etx ex- exe exo exs ext exx fbb fbe fbf fbo fbs fbt fbx feb fee fef feo fes fet fex ffe fff ffo ffs fft ffx fob foe fof foo fos fot fox fsb fse fsf fso fss fst fsx ftb fte ftf fto fts ftt ftx fxe fxs fxt fxx ob- obb obe obf obo obs obt obx oeb oee oef oeo oes oet oex of- ofb ofe off ofo ofs oft ofx oo- oob oof ooo oos oot oox os- osb ose osf oso oss ost osx ot- otb ote otf oto ots ott ox- oxb oxf oxo oxt oxx sbb sbe sbf sbo sbs sbt sbx se- seb see sef seo ses set sex sfb sfe sff sfo sfs sft sfx sob soe sof soo sos sot sox ss- ssb sse ssf sso sss sst ssx stb ste stf sto sts stt stx sxs sxt t-x tbb tbe tbf tbo tbs tbt te- teb tee tef teo tes tet tex tfb tfe tff tfo tfs tft tfx to- tob toe tof too tos tot tox tsb tse tsf tso tss tst tsx ttb tte ttf tto tts ttt ttx txe txf txs txt xbe xbx xee xes xet xex xfe xfs xft xfx xof xoo xos xot xox xsb xss xst xtf xts xtx xxo xxx