-er b-u bbb bbe bbk bbl bbr bbt bbu be- beb bee bek bel ber bet beu bkb bke bkk bkl bkr bkt blb ble blk bll blr blt blu brb bre brk brl brr brt bru btb bte btk btl btr btt btu bub bue buk bul bur but buu ebb ebe ebk ebl ebr ebt ebu eeb eee eek eel eer eet ekb eke ekl ekr ekt eku elb ele elk ell elr elt elu erb ere erk erl err ert eru etb ete etk etl etr ett etu eu- eub eue eul eur eut k-t kbb kbe kbk kbl kbr kbu ke- keb kee kek kel ker ket kkb kke kkk kkl kkr kkt kku kl- klb klr klt klu krk krl krr krt kru ktb kte ktk ktl ktr ktt ktu kub kue kuk kul kur kut kuu lbb lbe lbk lbl lbr lbt lbu leb lee lek lel ler let leu lkb lkl lkr lkt llb lle llk lll llr llt llu lrb lrk lrr lrt lru ltb lte ltk ltl ltr ltt ltu lub lue luk lul lur lut luu rbb rbe rbk rbl rbr rbt rbu re- reb ree rek rel rer ret reu rkb rke rkk rkt rku rle rll rlr rlt rlu rrb rrk rrl rrr rrt rru rtb rte rtk rtl rtr rtt rtu rub rue ruk rur rut ruu tbb tbe tbk tbl tbr tbt tbu te- teb tee tek tel ter tet teu tkb tke tkk tkl tkr tkt tle tlk tll tlr tlt tlu trb tre trk trl trr trt tru ttb tte ttk ttl ttr ttt ttu tub tue tuk tul tur tut tuu ubb ube ubk ubl ubr ubt ubu ueb uee uel uer uet ukb uke ukk ukl ukr uku ulb ule ulk ull ulr ult ulu ur- urb ure urk url urr urt uru utb ute utk utl utr utt utu uue uur uut uuu