-er b-u bbb bbc bbd bbe bbk bbr bbt bbu bcb bcc bcd bce bck bcr bct bcu bdb bdc bdd bde bdk bdr bdt bdu be- beb bec bed bee bek ber bet beu bkb bkc bke bkk bkr bkt brb brd bre brk brr brt bru btb btc btd bte btk btr btt btu bub buc bud bue buk bur but buu c-- cbb cbc cbd cbe cbk cbr cbt cbu ccb ccc ccd cce cck ccr cct ccu cdb cdc cdd cde cdk cdr cdt cdu ce- ceb cec ced cee cek cer cet ceu ckb ckc ckd ckt crb crc crd cre crk crr crt cru ctb ctc ctd cte ctk ctr ctt ctu cub cuc cud cue cuk cur cut cuu dbb dbc dbd dbe dbk dbr dbt dbu dcb dcc dcd dce dck dcr dct dcu ddb ddc ddd dde ddk ddr ddt ddu de- deb dec ded dee dek der det deu dkb dkc dke dkk dkr dkt dku drb drc drd dre drk drr drt dru dtb dtc dtd dte dtk dtr dtt dtu dub duc dud due duk dur dut ebb ebc ebd ebe ebk ebr ebt ebu ec- ecb ecc ecd ece eck ecr ect ecu ed- edb edc edd ede edk edr edt edu eeb eec eed eee eek eer eet ekb ekc ekd eke ekr ekt eku erb erc erd ere erk err ert eru etb etc etd ete etk etr ett etu eu- eub euc eud eue eur eut k-t kbb kbc kbd kbe kbk kbr kbu kcb kcc kcd kce kck kcr kct kcu kdb kdc kde kdk kdr kdt kdu ke- keb kec ked kee kek ker ket kkb kkc kke kkk kkr kkt kku krc krd krk krr krt kru ktb ktc kte ktk ktr ktt ktu kub kuc kud kue kuk kur kut kuu rbb rbc rbd rbe rbk rbr rbt rbu rcb rcc rcd rce rcr rct rcu rdb rdc rdd rde rdr rdt rdu re- reb rec red ree rek rer ret reu rkb rkc rke rkk rkt rku rrb rrc rrd rrk rrr rrt rru rtb rtc rtd rte rtk rtr rtt rtu rub ruc rud rue ruk rur rut ruu tbb tbc tbd tbe tbk tbr tbt tbu tcb tcc tcd tce tck tcr tct tcu tdb tdc tdd tde tdk tdr tdt tdu te- teb tec ted tee tek ter tet teu tkb tkc tke tkk tkr tkt trb trc trd tre trk trr trt tru ttb ttc ttd tte ttk ttr ttt ttu tub tuc tud tue tuk tur tut tuu ubb ubc ube ubk ubr ubt ubu ucb ucc ucd uce uck ucr uct ucu udb udc udd ude udk udr udt udu ueb uec ued uee uer uet ukb ukc uke ukk ukr uku ur- urb urc urd ure urk urr urt uru utb utc utd ute utk utr utt utu uuc uue uur uut uuu