-er b-u bbb bbc bbd bbe bbk bbr bbs bbt bbu bcb bcc bcd bce bck bcr bcs bct bcu bdb bdc bdd bde bdk bdr bds bdt bdu be- beb bec bed bee bek ber bes bet beu bkb bkc bke bkk bkr bks bkt brb brd bre brk brr brs brt bru bsb bsc bsd bse bsk bsr bss bst bsu btb btc btd bte btk btr bts btt btu bub buc bud bue buk bur bus but buu c-- cbb cbc cbd cbe cbk cbr cbs cbt cbu ccb ccc ccd cce cck ccr ccs cct ccu cdb cdc cdd cde cdk cdr cds cdt cdu ce- ceb cec ced cee cek cer ces cet ceu ckb ckc ckd cks ckt crb crc crd cre crk crr crs crt cru csb csc csd cse csk csr css cst csu ctb ctc ctd cte ctk ctr cts ctt ctu cub cuc cud cue cuk cur cus cut cuu dbb dbc dbd dbe dbk dbr dbs dbt dbu dcb dcc dcd dce dck dcr dcs dct dcu ddb ddc ddd dde ddk ddr dds ddt ddu de- deb dec ded dee dek der des det deu dkb dkc dke dkk dkr dks dkt dku drb drc drd dre drk drr drs drt dru dsb dsc dsd dse dsk dsr dss dst dsu dtb dtc dtd dte dtk dtr dts dtt dtu dub duc dud due duk dur dus dut ebb ebc ebd ebe ebk ebr ebs ebt ebu ec- ecb ecc ecd ece eck ecr ecs ect ecu ed- edb edc edd ede edk edr eds edt edu eeb eec eed eee eek eer ees eet ekb ekc ekd eke ekr eks ekt eku erb erc erd ere erk err ers ert eru es- esb esc esd ese esk esr ess est esu etb etc etd ete etk etr ets ett etu eu- eub euc eud eue eur eus eut k-t kbb kbc kbd kbe kbk kbr kbs kbu kcb kcc kcd kce kck kcr kcs kct kcu kdb kdc kde kdk kdr kds kdt kdu ke- keb kec ked kee kek ker kes ket kkb kkc kke kkk kkr kks kkt kku krc krd krk krr krs krt kru ksb ksc ksd kse ksk ksr kss kst ksu ktb ktc kte ktk ktr kts ktt ktu kub kuc kud kue kuk kur kus kut kuu rbb rbc rbd rbe rbk rbr rbs rbt rbu rcb rcc rcd rce rcr rcs rct rcu rdb rdc rdd rde rdr rds rdt rdu re- reb rec red ree rek rer res ret reu rkb rkc rke rkk rks rkt rku rrb rrc rrd rrk rrr rrs rrt rru rsb rsc rsd rse rsk rsr rss rst rsu rtb rtc rtd rte rtk rtr rts rtt rtu rub ruc rud rue ruk rur rus rut ruu sbb sbc sbd sbe sbk sbr sbs sbt sbu scb scc scd sce sck scr scs sct scu sdb sdc sdd sde sdk sdr sds sdt sdu se- seb sec sed see sek ser ses set seu sk- skb skc skd ske skk skr sks skt sku sr- srb src srd sre srk srr srs srt ss- ssb ssc ssd sse ssk ssr sss sst ssu stb stc std ste stk str sts stt stu sub suc sud sue suk sur sus sut suu tbb tbc tbd tbe tbk tbr tbs tbt tbu tcb tcc tcd tce tck tcr tcs tct tcu tdb tdc tdd tde tdk tdr tds tdt tdu te- teb tec ted tee tek ter tes tet teu tkb tkc tke tkk tkr tks tkt trb trc trd tre trk trr trs trt tru tsb tsc tsd tse tsk tsr tss tst tsu ttb ttc ttd tte ttk ttr tts ttt ttu tub tuc tud tue tuk tur tus tut tuu ubb ubc ube ubk ubr ubs ubt ubu ucb ucc ucd uce uck ucr ucs uct ucu udb udc udd ude udk udr uds udt udu ueb uec ued uee uer ues uet ukb ukc uke ukk ukr uku ur- urb urc urd ure urk urr urs urt uru usb usc usd use usk usr uss ust usu utb utc utd ute utk utr uts utt utu uuc uue uur uus uut uuu