-er b-u bbb bbd bbe bbo bbr bbs bbt bbu bdb bdd bde bdo bdr bds bdt bdu be- beb bed bee beo ber bes bet beu bob bod boe boo bor bos bot bou brb brd bre bro brr brs brt bru bsb bsd bse bso bsr bss bst bsu btb btd bte bto btr bts btt btu bub bud bue buo bur bus but buu dbb dbd dbe dbo dbr dbs dbt dbu ddb ddd dde ddo ddr dds ddt ddu de- deb ded dee deo der des det deu dob dod doe doo dor dos dot dou drb drd dre dro drr drs drt dru dsb dsd dse dso dsr dss dst dsu dtb dtd dte dto dtr dts dtt dtu dub dud due duo dur dus dut ebb ebd ebe ebo ebr ebs ebt ebu ed- edb edd ede edo edr eds edt edu eeb eed eee eeo eer ees eet eo- eob eod eoe eoo eor eos eot eou erb erd ere ero err ers ert eru es- esb esd ese eso esr ess est esu etb etd ete eto etr ets ett etu eu- eub eud eue eur eus eut ob- obb obd obe obo obr obs obt obu odb odd ode odo odr ods odt odu oeb oed oee oeo oer oes oet oo- oob ood ooo oor oos oot or- orb ord ore oro orr ors ort oru os- osb osd ose oso osr oss ost osu ot- otb otd ote oto otr ots ott otu ou- oud oue ouo our ous out rbb rbd rbe rbo rbr rbs rbt rbu rdb rdd rde rdo rdr rds rdt rdu re- reb red ree reo rer res ret reu rob rod roe roo ror ros rot rou rrb rrd rrr rrs rrt rru rsb rsd rse rso rsr rss rst rsu rtb rtd rte rto rtr rts rtt rtu rub rud rue ruo rur rus rut ruu sbb sbd sbe sbo sbr sbs sbt sbu sdb sdd sde sdo sdr sds sdt sdu se- seb sed see seo ser ses set seu sob sod soe soo sor sos sot sou sr- srb srd sre sro srr srs srt ss- ssb ssd sse sso ssr sss sst ssu stb std ste sto str sts stt stu sub sud sue suo sur sus sut suu tbb tbd tbe tbo tbr tbs tbt tbu tdb tdd tde tdo tdr tds tdt tdu te- teb ted tee teo ter tes tet teu to- tob tod toe too tor tos tot tou trb trd tre tro trr trs trt tru tsb tsd tse tso tsr tss tst tsu ttb ttd tte tto ttr tts ttt ttu tub tud tue tuo tur tus tut tuu ubb ube ubo ubr ubs ubt ubu udb udd ude udo udr uds udt udu ueb ued uee uer ues uet uob uod uoe uoo uor uos uot ur- urb urd ure uro urr urs urt uru usb usd use uso usr uss ust usu utb utd ute uto utr uts utt utu uue uur uus uut uuu