b-p bbb bbo bbp bbs bbt bbx bob boo bop bos bot box bpb bpo bpp bps bpt bpx bsb bso bsp bss bst bsx btb bto btp bts btt btx bxb bxo bxx ob- obb obo obp obs obt obx oo- oob ooo oop oos oot oox op- opb opo opp ops opt opx os- osb oso osp oss ost osx ot- otb oto otp ots ott ox- oxb oxo oxt oxx p-p pbb pbo pbp pbs pbt pbx pob poo pop pos pot pox ppb ppo ppp pps ppt ppx ps- psb pso psp pss pst psx pt- ptb pto ptp pts ptt ptx pxs pxt sbb sbo sbp sbs sbt sbx sob soo sop sos sot sox spb spo spp sps spt spx ss- ssb sso ssp sss sst ssx stb sto stp sts stt stx sxs sxt t-x tbb tbo tbp tbs tbt to- tob too top tos tot tox tpb tpo tpp tps tpt tpx tsb tso tsp tss tst tsx ttb tto ttp tts ttt ttx txs txt xbx xoo xop xos xot xox xpb xpo xpp xps xpt xsb xsp xss xst xtp xts xtx xxo xxp xxx