-er b-u bbb bbe bbq bbr bbt bbu be- beb bee beq ber bet beu bqe bqt brb bre brq brr brt bru btb bte btq btr btt btu bub bue bur but buu ebb ebe ebq ebr ebt ebu eeb eee eer eet eqe eqq eqt equ erb ere erq err ert eru etb ete etr ett etu eu- eub eue eur eut qbe qbq qee qet qqq qqu qrb qre qrt qru qtq qtr qu- que qur qut rbb rbe rbr rbt rbu re- reb ree req rer ret reu rrb rrq rrr rrt rru rtb rte rtq rtr rtt rtu rub rue rur rut ruu tbb tbe tbr tbt tbu te- teb tee teq ter tet teu trb tre trq trr trt tru ttb tte ttr ttt ttu tub tue tur tut tuu ubb ube ubr ubt ubu ueb uee uer uet ur- urb ure urr urt uru utb ute utr utt utu uue uur uut uuu