-er b-u bbb bbd bbe bbo bbr bbt bbu bdb bdd bde bdo bdr bdt bdu be- beb bed bee beo ber bet beu bob bod boe boo bor bot bou brb brd bre bro brr brt bru btb btd bte bto btr btt btu bub bud bue buo bur but buu dbb dbd dbe dbo dbr dbt dbu ddb ddd dde ddo ddr ddt ddu de- deb ded dee deo der det deu dob dod doe doo dor dot dou drb drd dre dro drr drt dru dtb dtd dte dto dtr dtt dtu dub dud due duo dur dut ebb ebd ebe ebo ebr ebt ebu ed- edb edd ede edo edr edt edu eeb eed eee eeo eer eet eo- eob eod eoe eoo eor eot eou erb erd ere ero err ert eru etb etd ete eto etr ett etu eu- eub eud eue eur eut ob- obb obd obe obo obr obt obu odb odd ode odo odr odt odu oeb oed oee oeo oer oet oo- oob ood ooo oor oot or- orb ord ore oro orr ort oru ot- otb otd ote oto otr ott otu ou- oud oue ouo our out rbb rbd rbe rbo rbr rbt rbu rdb rdd rde rdo rdr rdt rdu re- reb red ree reo rer ret reu rob rod roe roo ror rot rou rrb rrd rrr rrt rru rtb rtd rte rto rtr rtt rtu rub rud rue ruo rur rut ruu tbb tbd tbe tbo tbr tbt tbu tdb tdd tde tdo tdr tdt tdu te- teb ted tee teo ter tet teu to- tob tod toe too tor tot tou trb trd tre tro trr trt tru ttb ttd tte tto ttr ttt ttu tub tud tue tuo tur tut tuu ubb ube ubo ubr ubt ubu udb udd ude udo udr udt udu ueb ued uee uer uet uob uod uoe uoo uor uot ur- urb urd ure uro urr urt uru utb utd ute uto utr utt utu uue uur uut uuu