-er c-- ccc cce cch cck cco ccr ccs ce- cec cee ceh cek ceo cer ces ch- chc che chh chk cho chr chs ckc ckh cko cks co- coc coe coh cok coo cor cos crc cre crh crk cro crr crs csc cse csh csk cso csr css ec- ecc ece ech eck eco ecr ecs eec eee eek eeo eer ees ehc ehe ehh eho ehr ehs ekc eke ekh eko ekr eks eo- eoc eoe eoh eok eoo eor eos erc ere erh erk ero err ers es- esc ese esh esk eso esr ess hcc hce hch hck hco hcr hcs he- hec hee heh hek heo her hes hhc hhe hhh hhk hho hhr hhs hkh hkk hko hkr hks hoc hoe hoh hok hoo hor hos hr- hrc hre hrh hrk hro hrr hrs hsc hse hsh hsk hsr hss kcc kce kch kck kcr kcs ke- kec kee keh kek keo ker kes khe khh khk kho khr khs kkc kke kkh kkk kkr kks koc koe koh kok koo kor kos krc krk kro krr krs ksc kse ksh ksk kso ksr kss oc- occ och ock oco ocr ocs oec oee oeh oeo oer oes ohc ohe ohh oho ohr ohs okc oke okk oko okr oks oo- ooc ooh ook ooo oor oos or- orc ore orh ork oro orr ors os- osc ose osh osk oso osr oss rcc rce rch rco rcr rcs re- rec ree reh rek reo rer res rh- rhc rhe rhh rho rhr rhs rkc rke rkk rko rks roc roe roh rok roo ror ros rrc rrh rrk rrr rrs rsc rse rsh rsk rso rsr rss scc sce sch sck sco scr scs se- sec see seh sek seo ser ses sh- shc she shh shk sho shr shs sk- skc ske skh skk sko skr sks soc soe soh sok soo sor sos sr- src sre srh srk sro srr srs ss- ssc sse ssh ssk sso ssr sss