-er bbb bbd bbe bbl bbr bbt bdb bdd bde bdl bdr bdt be- beb bed bee bel ber bet blb bld ble bll blr blt brb brd bre brl brr brt btb btd bte btl btr btt dbb dbd dbe dbl dbr dbt ddb ddd dde ddl ddr ddt de- deb ded dee del der det dl- dlb dld dle dll dlr dlt drb drd dre drl drr drt dtb dtd dte dtl dtr dtt ebb ebd ebe ebl ebr ebt ed- edb edd ede edl edr edt eeb eed eee eel eer eet elb eld ele ell elr elt erb erd ere erl err ert etb etd ete etl etr ett lbb lbd lbe lbl lbr lbt ldb ldd lde ldl ldr ldt leb led lee lel ler let llb lld lle lll llr llt lrb lrd lrr lrt ltb ltd lte ltl ltr ltt rbb rbd rbe rbl rbr rbt rdb rdd rde rdl rdr rdt re- reb red ree rel rer ret rld rle rll rlr rlt rrb rrd rrl rrr rrt rtb rtd rte rtl rtr rtt tbb tbd tbe tbl tbr tbt tdb tdd tde tdl tdr tdt te- teb ted tee tel ter tet tld tle tll tlr tlt trb trd tre trl trr trt ttb ttd tte ttl ttr ttt