-er bbb bbe bbi bbk bbn bbo bbr be- beb bee bei bek ben beo ber bi- bib bie bii bik bin bio bir bkb bke bkk bkn bko bkr bnb bne bni bnk bnn bno bnr bob boe boi bok bon boo bor brb bre bri brk brn bro brr ebb ebe ebi ebk ebn ebo ebr eeb eee eek een eeo eer eib eie eii eik ein eio eir ekb eke eki eko ekr en- enb ene eni enk enn eno enr eo- eob eoe eoi eok eon eoo eor erb ere eri erk ern ero err ibb ibe ibi ibk ibn ibo ibr ie- iee iei iek ien ier iib iie iii iin iio iir ikb ike iki ikk iko ikr in- inb ine ini ink inn ino inr io- iob ioe ioi ion ioo ior ir- irb ire iri irk irn iro irr kbb kbe kbi kbk kbn kbo kbr ke- keb kee kei kek ken keo ker kib kie kii kik kin kio kir kkb kke kki kkk kkn kkr kn- kne kni knk knn kno knr kob koe koi kok kon koo kor kri krk krn kro krr n-i nbb nbe nbi nbk nbn nbo nbr ne- neb nee nei nek nen neo ner nib nie nii nik nin nio nir nke nki nkk nkn nko nkr nnb nne nni nnk nnn nno no- nob noe noi nok non noo nor nrb nre nri nrk nrn nro nrr o-i ob- obb obe obi obk obn obo obr oeb oee oei oen oeo oer oib oie oii oik oin oio oir okb oke oki okk oko okr on- onb one oni onk onn ono onr oo- oob ooi ook oon ooo oor or- orb ore ori ork orn oro orr rbb rbe rbi rbk rbn rbo rbr re- reb ree rei rek ren reo rer rib rie rii rik rin rio rir rkb rke rkk rko rnb rni rnn rno rnr rob roe roi rok ron roo ror rrb rri rrk rrn rrr