-er b-p bbb bbe bbn bbo bbp bbr be- beb bee ben beo bep ber bnb bne bnn bno bnp bnr bob boe bon boo bop bor bpb bpe bpn bpo bpp bpr brb bre brn bro brp brr ebb ebe ebn ebo ebp ebr eeb eee een eeo eep eer en- enb ene enn eno enp enr eo- eob eoe eon eoo eop eor ep- epb epe epn epo epp epr erb ere ern ero erp err nbb nbe nbn nbo nbp nbr ne- neb nee nen neo nep ner nnb nne nnn nno nnp no- nob noe non noo nop nor npb npe npn npo npp npr nrb nre nrn nro nrp nrr ob- obb obe obn obo obp obr oeb oee oen oeo oep oer on- onb one onn ono onp onr oo- oob oon ooo oop oor op- opb ope opn opo opp opr or- orb ore orn oro orp orr p-p pbb pbe pbn pbo pbp pbr peb pee pen peo pep per pn- pnb pne pnn pno pnp pnr pob poe pon poo pop por ppb ppe ppn ppo ppp ppr prb pre prn pro prp prr rbb rbe rbn rbo rbp rbr re- reb ree ren reo rep rer rnb rnn rno rnp rnr rob roe ron roo rop ror rpb rpe rpn rpo rpp rpr rrb rrn rrp rrr