-er c-- ccc cce cco ccr ccs ccu ce- cec cee ceo cer ces ceu co- coc coe coo cor cos cou crc cre cro crr crs cru csc cse cso csr css csu cuc cue cuo cur cus cuu ec- ecc ece eco ecr ecs ecu eec eee eeo eer ees eo- eoc eoe eoo eor eos eou erc ere ero err ers eru es- esc ese eso esr ess esu eu- euc eue eur eus oc- occ oco ocr ocs ocu oec oee oeo oer oes oo- ooc ooo oor oos or- orc ore oro orr ors oru os- osc ose oso osr oss osu ou- ouc oue ouo our ous rcc rce rco rcr rcs rcu re- rec ree reo rer res reu roc roe roo ror ros rou rrc rrr rrs rru rsc rse rso rsr rss rsu ruc rue ruo rur rus ruu scc sce sco scr scs scu se- sec see seo ser ses seu soc soe soo sor sos sou sr- src sre sro srr srs ss- ssc sse sso ssr sss ssu suc sue suo sur sus suu ucc uce uco ucr ucs ucu uec uee uer ues uoc uoe uoo uor uos ur- urc ure uro urr urs uru usc use uso usr uss usu uuc uue uur uus uuu