-er c-- ccc ccd cce cck cco ccr ccs ccu cdc cdd cde cdk cdo cdr cds cdu ce- cec ced cee cek ceo cer ces ceu ckc ckd cko cks co- coc cod coe cok coo cor cos cou crc crd cre crk cro crr crs cru csc csd cse csk cso csr css csu cuc cud cue cuk cuo cur cus cuu dcc dcd dce dck dco dcr dcs dcu ddc ddd dde ddk ddo ddr dds ddu de- dec ded dee dek deo der des deu dkc dke dkk dko dkr dks dku doc dod doe dok doo dor dos dou drc drd dre drk dro drr drs dru dsc dsd dse dsk dso dsr dss dsu duc dud due duk duo dur dus ec- ecc ecd ece eck eco ecr ecs ecu ed- edc edd ede edk edo edr eds edu eec eed eee eek eeo eer ees ekc ekd eke eko ekr eks eku eo- eoc eod eoe eok eoo eor eos eou erc erd ere erk ero err ers eru es- esc esd ese esk eso esr ess esu eu- euc eud eue eur eus kcc kcd kce kck kcr kcs kcu kdc kde kdk kdo kdr kds kdu ke- kec ked kee kek keo ker kes kkc kke kkk kkr kks kku koc kod koe kok koo kor kos kou krc krd krk kro krr krs kru ksc ksd kse ksk kso ksr kss ksu kuc kud kue kuk kur kus kuu oc- occ ocd ock oco ocr ocs ocu odc odd ode odo odr ods odu oec oed oee oeo oer oes okc okd oke okk oko okr oks oku oo- ooc ood ook ooo oor oos or- orc ord ore ork oro orr ors oru os- osc osd ose osk oso osr oss osu ou- ouc oud oue ouk ouo our ous rcc rcd rce rco rcr rcs rcu rdc rdd rde rdo rdr rds rdu re- rec red ree rek reo rer res reu rkc rke rkk rko rks rku roc rod roe rok roo ror ros rou rrc rrd rrk rrr rrs rru rsc rsd rse rsk rso rsr rss rsu ruc rud rue ruk ruo rur rus ruu scc scd sce sck sco scr scs scu sdc sdd sde sdk sdo sdr sds sdu se- sec sed see sek seo ser ses seu sk- skc skd ske skk sko skr sks sku soc sod soe sok soo sor sos sou sr- src srd sre srk sro srr srs ss- ssc ssd sse ssk sso ssr sss ssu suc sud sue suk suo sur sus suu ucc ucd uce uck uco ucr ucs ucu udc udd ude udk udo udr uds udu uec ued uee uer ues ukc uke ukk ukr uku uoc uod uoe uok uoo uor uos ur- urc urd ure urk uro urr urs uru usc usd use usk uso usr uss usu uuc uue uur uus uuu