-er b-p bbb bbe bbi bbk bbn bbo bbp bbr be- beb bee bei bek ben beo bep ber bi- bib bie bii bik bin bio bip bir bkb bke bkk bkn bko bkp bkr bnb bne bni bnk bnn bno bnp bnr bob boe boi bok bon boo bop bor bpb bpe bpi bpn bpo bpp bpr brb bre bri brk brn bro brp brr ebb ebe ebi ebk ebn ebo ebp ebr eeb eee eek een eeo eep eer eib eie eii eik ein eio eip eir ekb eke eki eko ekp ekr en- enb ene eni enk enn eno enp enr eo- eob eoe eoi eok eon eoo eop eor ep- epb epe epi epn epo epp epr erb ere eri erk ern ero erp err ibb ibe ibi ibk ibn ibo ibp ibr ie- iee iei iek ien iep ier iib iie iii iin iio iip iir ikb ike iki ikk iko ikr in- inb ine ini ink inn ino inp inr io- iob ioe ioi ion ioo iop ior ipb ipe ipi ipn ipo ipp ipr ir- irb ire iri irk irn iro irp irr kbb kbe kbi kbk kbn kbo kbp kbr ke- keb kee kei kek ken keo kep ker kib kie kii kik kin kio kip kir kkb kke kki kkk kkn kkp kkr kn- kne kni knk knn kno knp knr kob koe koi kok kon koo kop kor kpe kpi kpk kpn kpo kpp kpr kri krk krn kro krp krr n-i nbb nbe nbi nbk nbn nbo nbp nbr ne- neb nee nei nek nen neo nep ner nib nie nii nik nin nio nip nir nke nki nkk nkn nko nkp nkr nnb nne nni nnk nnn nno nnp no- nob noe noi nok non noo nop nor npb npe npi npn npo npp npr nrb nre nri nrk nrn nro nrp nrr o-i ob- obb obe obi obk obn obo obp obr oeb oee oei oen oeo oep oer oib oie oii oik oin oio oip oir okb oke oki okk oko okp okr on- onb one oni onk onn ono onp onr oo- oob ooi ook oon ooo oop oor op- opb ope opi opk opn opo opp opr or- orb ore ori ork orn oro orp orr p-p pbb pbe pbi pbk pbn pbo pbp pbr peb pee pei pek pen peo pep per pib pie pii pik pin pio pip pir pkb pke pki pkn pko pkp pkr pn- pnb pne pni pnk pnn pno pnp pnr pob poe poi pok pon poo pop por ppb ppe ppi ppk ppn ppo ppp ppr prb pre pri prk prn pro prp prr rbb rbe rbi rbk rbn rbo rbp rbr re- reb ree rei rek ren reo rep rer rib rie rii rik rin rio rip rir rkb rke rkk rko rkp rnb rni rnn rno rnp rnr rob roe roi rok ron roo rop ror rpb rpe rpi rpk rpn rpo rpp rpr rrb rri rrk rrn rrp rrr