b-p bbb bbi bbo bbp bbr bi- bib bii bio bip bir bob boi boo bop bor bpb bpi bpo bpp bpr brb bri bro brp brr ibb ibi ibo ibp ibr iib iii iio iip iir io- iob ioi ioo iop ior ipb ipi ipo ipp ipr ir- irb iri iro irp irr o-i ob- obb obi obo obp obr oib oii oio oip oir oo- oob ooi ooo oop oor op- opb opi opo opp opr or- orb ori oro orp orr p-p pbb pbi pbo pbp pbr pib pii pio pip pir pob poi poo pop por ppb ppi ppo ppp ppr prb pri pro prp prr rbb rbi rbo rbp rbr rib rii rio rip rir rob roi roo rop ror rpb rpi rpo rpp rpr rrb rri rrp rrr