-er c-- ccc cce cco ccr ccs ccu ccv ce- cec cee ceo cer ces ceu cev co- coc coe coo cor cos cou cov crc cre cro crr crs cru crv csc cse cso csr css csu csv cuc cue cuo cur cus cuu cuv cvc cve cvo cvr cvs cvu cvv ec- ecc ece eco ecr ecs ecu ecv eec eee eeo eer ees eev eo- eoc eoe eoo eor eos eou erc ere ero err ers eru erv es- esc ese eso esr ess esu esv eu- euc eue eur eus euv evc eve evo evr evs evv oc- occ oco ocr ocs ocu ocv oec oee oeo oer oes oo- ooc ooo oor oos oov or- orc ore oro orr ors oru orv os- osc ose oso osr oss osu osv ou- ouc oue ouo our ous ov- ovc ove ovo ovs ovv rcc rce rco rcr rcs rcu rcv re- rec ree reo rer res reu rev roc roe roo ror ros rou rov rrc rrr rrs rru rsc rse rso rsr rss rsu rsv ruc rue ruo rur rus ruu ruv rvc rve rvo rvr rvs rvu rvv scc sce sco scr scs scu scv se- sec see seo ser ses seu sev soc soe soo sor sos sou sov sr- src sre sro srr srs srv ss- ssc sse sso ssr sss ssu ssv suc sue suo sur sus suu suv svc sve svo svr svs svu svv ucc uce uco ucr ucs ucu ucv uec uee uer ues uoc uoe uoo uor uos ur- urc ure uro urr urs uru usc use uso usr uss usu usv uuc uue uur uus uuu uvc uve uvo uvs uvu uvv v-e vcc vce vco vcr vcs vcu vec vee veo ver ves veu voc voe voo vor vos vou vov vrc vre vrr vrs vru vsc vse vso vsr vss vsu vsv vue vur vus vuv vvc vvo vvr vvs vvv