b-p bbb bbe bbi bbp bbs be- beb bee bei bep bes bi- bib bie bii bip bis bpb bpe bpi bpp bps bsb bse bsi bsp bss ebb ebe ebi ebp ebs eeb eee eep ees eib eie eii eip eis ep- epb epe epi epp eps es- esb ese esi esp ess ibb ibe ibi ibp ibs ie- iee iei iep ies iib iie iii iip iis ipb ipe ipi ipp ips is- isb ise isi isp iss p-p pbb pbe pbi pbp pbs peb pee pei pep pes pib pie pii pip pis ppb ppe ppi ppp pps ps- psb pse psi psp pss sbb sbe sbi sbp sbs se- seb see sei sep ses sib sie sii sip sis spb spe spi spp sps ss- ssb sse ssi ssp sss