-er c-- ccc cce cco ccr ccs ccu ccx ce- cec cee ceo cer ces ceu cex co- coc coe coo cor cos cou cox crc cre cro crr crs cru crx csc cse cso csr css csu csx cuc cue cuo cur cus cuu cxc cxo cxr cxs cxx ec- ecc ece eco ecr ecs ecu ecx eec eee eeo eer ees eex eo- eoc eoe eoo eor eos eou erc ere ero err ers eru es- esc ese eso esr ess esu esx eu- euc eue eur eus eux ex- exc exe exo exr exs exu exx oc- occ oco ocr ocs ocu ocx oec oee oeo oer oes oex oo- ooc ooo oor oos oox or- orc ore oro orr ors oru orx os- osc ose oso osr oss osu osx ou- ouc oue ouo our ous ox- oxc oxo oxx rcc rce rco rcr rcs rcu rcx re- rec ree reo rer res reu rex roc roe roo ror ros rou rox rrc rrr rrs rru rsc rse rso rsr rss rsu rsx ruc rue ruo rur rus ruu rux rxr rxs scc sce sco scr scs scu scx se- sec see seo ser ses seu sex soc soe soo sor sos sou sox sr- src sre sro srr srs srx ss- ssc sse sso ssr sss ssu ssx suc sue suo sur sus suu sux sxc sxs sxu ucc uce uco ucr ucs ucu uec uee uer ues uoc uoe uoo uor uos uox ur- urc ure uro urr urs uru urx usc use uso usr uss usu usx uuc uue uur uus uuu uxc uxo uxr uxu xcr xcx xee xer xes xeu xex xoc xoo xor xos xox xrc xrx xsc xss xue xus xxo xxx