b-p bbb bbi bbo bbp bbs bbt bbx bi- bib bii bio bip bis bit bix bob boi boo bop bos bot box bpb bpi bpo bpp bps bpt bpx bsb bsi bso bsp bss bst bsx btb bti bto btp bts btt btx bxb bxi bxo bxx ibb ibi ibo ibp ibs ibt ibx iib iii iio iip iis iit iix io- iob ioi ioo iop ios iot ipb ipi ipo ipp ips ipt ipx is- isb isi iso isp iss ist itb iti ito itp its itt itx ixi o-i ob- obb obi obo obp obs obt obx oib oii oio oip ois oit oo- oob ooi ooo oop oos oot oox op- opb opi opo opp ops opt opx os- osb osi oso osp oss ost osx ot- otb oti oto otp ots ott ox- oxb oxi oxo oxt oxx p-p pbb pbi pbo pbp pbs pbt pbx pib pii pio pip pis pit pix pob poi poo pop pos pot pox ppb ppi ppo ppp pps ppt ppx ps- psb psi pso psp pss pst psx pt- ptb pti pto ptp pts ptt ptx pxs pxt sbb sbi sbo sbp sbs sbt sbx sib sii sio sip sis sit six sob soi soo sop sos sot sox spb spi spo spp sps spt spx ss- ssb ssi sso ssp sss sst ssx stb sti sto stp sts stt stx sxi sxs sxt t-x tbb tbi tbo tbp tbs tbt tib tii tio tip tis tit tix to- tob toi too top tos tot tox tpb tpi tpo tpp tps tpt tpx tsb tsi tso tsp tss tst tsx ttb tti tto ttp tts ttt ttx txi txs txt xbx xii xio xis xit xix xoi xoo xop xos xot xox xpb xpo xpp xps xpt xsb xsi xsp xss xst xti xtp xts xtx xxi xxo xxp xxx