-er bbb bbe bbk bbl bbr be- beb bee bek bel ber bkb bke bkk bkl bkr blb ble blk bll blr brb bre brk brl brr ebb ebe ebk ebl ebr eeb eee eek eel eer ekb eke ekl ekr elb ele elk ell elr erb ere erk erl err kbb kbe kbk kbl kbr ke- keb kee kek kel ker kkb kke kkk kkl kkr kl- klb klr krk krl krr lbb lbe lbk lbl lbr leb lee lek lel ler lkb lkl lkr llb lle llk lll llr lrb lrk lrr rbb rbe rbk rbl rbr re- reb ree rek rel rer rkb rke rkk rle rll rlr rrb rrk rrl rrr