-er bbb bbe bbi bbo bbr be- beb bee bei beo ber bez bi- bib bie bii bio bir biz bob boe boi boo bor boz brb bre bri bro brr brz bze bzo bzr bzz ebb ebe ebi ebo ebr eeb eee eeo eer eib eie eii eio eir eo- eob eoe eoi eoo eor erb ere eri ero err erz eze ezo ezr ezz ibb ibe ibi ibo ibr ibz ie- iee iei ier iib iie iii iio iir io- iob ioe ioi ioo ior ir- irb ire iri iro irr ize izi izo izz o-i ob- obb obe obi obo obr oeb oee oei oeo oer oib oie oii oio oir oiz oo- oob ooi ooo oor or- orb ore ori oro orr orz oze ozo ozz rbb rbe rbi rbo rbr re- reb ree rei reo rer rez rib rie rii rio rir riz rob roe roi roo ror roz rrb rri rrr rzb rze rzo zbb zbr zeb zee zeo zer zez zib zie zio zir ziz zo- zob zoe zoi zoo zor zro zzr zzz