-er c-- ccc cce cch cck cco ccr ccs ccx ce- cec cee ceh cek ceo cer ces cex ch- chc che chh chk cho chr chs chx ckc ckh cko cks ckx co- coc coe coh cok coo cor cos cox crc cre crh crk cro crr crs crx csc cse csh csk cso csr css csx cxc cxh cxk cxo cxr cxs cxx ec- ecc ece ech eck eco ecr ecs ecx eec eee eek eeo eer ees eex 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 esx ex- exc exe exh exo exr exs exx hcc hce hch hck hco hcr hcs he- hec hee heh hek heo her hes hex hhc hhe hhh hhk hho hhr hhs hkh hkk hko hkr hks hoc hoe hoh hok hoo hor hos hox hr- hrc hre hrh hrk hro hrr hrs hsc hse hsh hsk hsr hss hsx hxc kcc kce kch kck kcr kcs kcx ke- kec kee keh kek keo ker kes kex 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 kxo oc- occ och ock oco ocr ocs ocx oec oee oeh oeo oer oes oex ohc ohe ohh oho ohr ohs okc oke okk oko okr oks oo- ooc ooh ook ooo oor oos oox or- orc ore orh ork oro orr ors orx os- osc ose osh osk oso osr oss osx ox- oxc oxo oxx rcc rce rch rco rcr rcs rcx re- rec ree reh rek reo rer res rex rh- rhc rhe rhh rho rhr rhs rkc rke rkk rko rks roc roe roh rok roo ror ros rox rrc rrh rrk rrr rrs rsc rse rsh rsk rso rsr rss rsx rxr rxs scc sce sch sck sco scr scs scx se- sec see seh sek seo ser ses sex sh- shc she shh shk sho shr shs sk- skc ske skh skk sko skr sks skx soc soe soh sok soo sor sos sox sr- src sre srh srk sro srr srs srx ss- ssc sse ssh ssk sso ssr sss ssx sxc sxs xch xcr xcx xee xer xes xex xke xks xoc xok xoo xor xos xox xrc xrx xsc xss xxo xxx