b-p bbb bbe bbo bbp bbs be- beb bee beo bep bes bob boe boo bop bos bpb bpe bpo bpp bps bsb bse bso bsp bss ebb ebe ebo ebp ebs eeb eee eeo eep ees eo- eob eoe eoo eop eos ep- epb epe epo epp eps es- esb ese eso esp ess ob- obb obe obo obp obs oeb oee oeo oep oes oo- oob ooo oop oos op- opb ope opo opp ops os- osb ose oso osp oss p-p pbb pbe pbo pbp pbs peb pee peo pep pes pob poe poo pop pos ppb ppe ppo ppp pps ps- psb pse pso psp pss sbb sbe sbo sbp sbs se- seb see seo sep ses sob soe soo sop sos spb spe spo spp sps ss- ssb sse sso ssp sss