-er c-- ccc ccd cce cco ccr ccs ccu ccx cdc cdd cde cdo cdr cds cdu cdx ce- cec ced cee ceo cer ces ceu cex co- coc cod coe coo cor cos cou cox crc crd cre cro crr crs cru crx csc csd cse cso csr css csu csx cuc cud cue cuo cur cus cuu cxc cxo cxr cxs cxx dcc dcd dce dco dcr dcs dcu dcx ddc ddd dde ddo ddr dds ddu ddx de- dec ded dee deo der des deu dex doc dod doe doo dor dos dou dox drc drd dre dro drr drs dru drx dsc dsd dse dso dsr dss dsu dsx duc dud due duo dur dus dux dxc dxd dxo dxr dxs dxx ec- ecc ecd ece eco ecr ecs ecu ecx ed- edc edd ede edo edr eds edu edx eec eed eee eeo eer ees eex eo- eoc eod eoe eoo eor eos eou erc erd ere ero err ers eru es- esc esd ese eso esr ess esu esx eu- euc eud eue eur eus eux ex- exc exd exe exo exr exs exu exx oc- occ ocd oco ocr ocs ocu ocx odc odd ode odo odr ods odu oec oed oee oeo oer oes oex oo- ooc ood ooo oor oos oox or- orc ord ore oro orr ors oru orx os- osc osd ose oso osr oss osu osx ou- ouc oud oue ouo our ous ox- oxc oxo oxx rcc rcd rce rco rcr rcs rcu rcx rdc rdd rde rdo rdr rds rdu rdx re- rec red ree reo rer res reu rex roc rod roe roo ror ros rou rox rrc rrd rrr rrs rru rsc rsd rse rso rsr rss rsu rsx ruc rud rue ruo rur rus ruu rux rxr rxs scc scd sce sco scr scs scu scx sdc sdd sde sdo sdr sds sdu se- sec sed see seo ser ses seu sex soc sod soe soo sor sos sou sox sr- src srd sre sro srr srs srx ss- ssc ssd sse sso ssr sss ssu ssx suc sud sue suo sur sus suu sux sxc sxs sxu ucc ucd uce uco ucr ucs ucu udc udd ude udo udr uds udu udx uec ued uee uer ues uoc uod uoe uoo uor uos uox ur- urc urd ure uro urr urs uru urx usc usd use uso usr uss usu usx uuc uue uur uus uuu uxc uxo uxr uxu xcd xcr xcx xdc xde xdr xds xed xee xer xes xeu xex xoc xod xoo xor xos xox xrc xrd xrx xsc xss xue xus xxo xxx