-er bbb bbe bbl bbr bbt be- beb bee bel ber bet blb ble bll blr blt brb bre brl brr brt btb bte btl btr btt ebb ebe ebl ebr ebt eeb eee eel eer eet elb ele ell elr elt erb ere erl err ert etb ete etl etr ett lbb lbe lbl lbr lbt leb lee lel ler let llb lle lll llr llt lrb lrr lrt ltb lte ltl ltr ltt rbb rbe rbl rbr rbt re- reb ree rel rer ret rle rll rlr rlt rrb rrl rrr rrt rtb rte rtl rtr rtt tbb tbe tbl tbr tbt te- teb tee tel ter tet tle tll tlr tlt trb tre trl trr trt ttb tte ttl ttr ttt