-er bbb bbd bbe bbi bbr bbt bdb bdd bde bdi bdr bdt be- beb bed bee bei ber bet bi- bib bid bie bii bir bit brb brd bre bri brr brt btb btd bte bti btr btt dbb dbd dbe dbi dbr dbt ddb ddd dde ddi ddr ddt de- deb ded dee dei der det di- dib did die dii dir dit drb drd dre dri drr drt dtb dtd dte dti dtr dtt ebb ebd ebe ebi ebr ebt ed- edb edd ede edi edr edt eeb eed eee eer eet eib eid eie eii eir eit erb erd ere eri err ert etb etd ete eti etr ett i-d ibb ibd ibe ibi ibr ibt idb idd ide idi idr idt ie- ied iee iei ier iet iib iid iie iii iir iit ir- irb ird ire iri irr irt itb itd ite iti itt rbb rbd rbe rbi rbr rbt rdb rdd rde rdi rdr rdt re- reb red ree rei rer ret rib rid rie rii rir rit rrb rrd rri rrr rrt rtb rtd rte rti rtr rtt tbb tbd tbe tbi tbr tbt tdb tdd tde tdi tdr tdt te- teb ted tee tei ter tet tib tid tie tii tir tit trb trd tre tri trr trt ttb ttd tte tti ttr ttt