b-p bbb bbe bbi bbo bbp bbs be- beb bee bei beo bep bes bi- bib bie bii bio bip bis bob boe boi boo bop bos bpb bpe bpi bpo bpp bps bsb bse bsi bso bsp bss ebb ebe ebi ebo ebp ebs eeb eee eeo eep ees eib eie eii eio eip eis eo- eob eoe eoi eoo eop eos ep- epb epe epi epo epp eps es- esb ese esi eso esp ess ibb ibe ibi ibo ibp ibs ie- iee iei iep ies iib iie iii iio iip iis io- iob ioe ioi ioo iop ios ipb ipe ipi ipo ipp ips is- isb ise isi iso isp iss o-i ob- obb obe obi obo obp obs oeb oee oei oeo oep oes oib oie oii oio oip ois oo- oob ooi ooo oop oos op- opb ope opi opo opp ops os- osb ose osi oso osp oss p-p pbb pbe pbi pbo pbp pbs peb pee pei peo pep pes pib pie pii pio pip pis pob poe poi poo pop pos ppb ppe ppi ppo ppp pps ps- psb pse psi pso psp pss sbb sbe sbi sbo sbp sbs se- seb see sei seo sep ses sib sie sii sio sip sis sob soe soi soo sop sos spb spe spi spo spp sps ss- ssb sse ssi sso ssp sss