-er bbb bbe bbf bbl bbr be- beb bee bef bel ber bfb bfe bff bfl bfr blb ble blf bll blr brb bre brf brl brr ebb ebe ebf ebl ebr eeb eee eef eel eer ef- efb efe eff efl efr elb ele elf ell elr erb ere erf erl err fbb fbe fbf fbl fbr feb fee fef fel fer ffe fff ffl ffr flb fle flf fll flr frb fre frf frl frr lbb lbe lbf lbl lbr leb lee lef lel ler lfb lfe lff lfl lfr llb lle llf lll llr lrb lrf lrr rbb rbe rbf rbl rbr re- reb ree ref rel rer rfb rfe rff rfl rfr rle rlf rll rlr rrb rrf rrl rrr