b-p bbb bbe bbk bbo bbp bbs bbt bbx be- beb bee bek beo bep bes bet bex bkb bke bkk bko bkp bks bkt bkx bob boe bok boo bop bos bot box bpb bpe bpo bpp bps bpt bpx bsb bse bsk bso bsp bss bst bsx btb bte btk bto btp bts btt btx bxb bxo bxx ebb ebe ebk ebo ebp ebs ebt ebx eeb eee eek eeo eep ees eet eex ekb eke eko ekp eks ekt eo- eob eoe eok eoo eop eos eot ep- epb epe epo epp eps ept epx es- esb ese esk eso esp ess est esx etb ete etk eto etp ets ett etx ex- exe exo exp exs ext exx k-t kbb kbe kbk kbo kbp kbs kbx ke- keb kee kek keo kep kes ket kex kkb kke kkk kkp kks kkt kob koe kok koo kop kos kot kpe kpk kpo kpp kps kpt ksb kse ksk kso ksp kss kst ktb kte ktk kto ktp kts ktt kxo ob- obb obe obk obo obp obs obt obx oeb oee oeo oep oes oet oex okb oke okk oko okp oks oo- oob ook ooo oop oos oot oox op- opb ope opk opo opp ops opt opx os- osb ose osk oso osp oss ost osx ot- otb ote otk oto otp ots ott ox- oxb oxo oxt oxx p-p pbb pbe pbk pbo pbp pbs pbt pbx peb pee pek peo pep pes pet pex pkb pke pko pkp pks pkt pob poe pok poo pop pos pot pox ppb ppe ppk ppo ppp pps ppt ppx ps- psb pse psk pso psp pss pst psx pt- ptb pte ptk pto ptp pts ptt ptx pxe pxk pxs pxt sbb sbe sbk sbo sbp sbs sbt sbx se- seb see sek seo sep ses set sex sk- skb ske skk sko skp sks skt skx sob soe sok soo sop sos sot sox spb spe spk spo spp sps spt spx ss- ssb sse ssk sso ssp sss sst ssx stb ste stk sto stp sts stt stx sxs sxt t-x tbb tbe tbk tbo tbp tbs tbt te- teb tee tek teo tep tes tet tex tkb tke tkk tko tkp tks tkt to- tob toe tok too top tos tot tox tpb tpe tpk tpo tpp tps tpt tpx tsb tse tsk tso tsp tss tst tsx ttb tte ttk tto ttp tts ttt ttx txe txk txs txt xbe xbx xee xep xes xet xex xkb xke xks xok xoo xop xos xot xox xpb xpe xpo xpp xps xpt xsb xsp xss xst xtp xts xtx xxo xxp xxx