-er c-- ccc cce cck ccr ccs ccu ce- cec cee cek cer ces ceu ckc cks crc cre crk crr crs cru csc cse csk csr css csu cuc cue cuk cur cus cuu ec- ecc ece eck ecr ecs ecu eec eee eek eer ees ekc eke ekr eks eku erc ere erk err ers eru es- esc ese esk esr ess esu eu- euc eue eur eus kcc kce kck kcr kcs kcu ke- kec kee kek ker kes kkc kke kkk kkr kks kku krc krk krr krs kru ksc kse ksk ksr kss ksu kuc kue kuk kur kus kuu rcc rce rcr rcs rcu re- rec ree rek rer res reu rkc rke rkk rks rku rrc rrk rrr rrs rru rsc rse rsk rsr rss rsu ruc rue ruk rur rus ruu scc sce sck scr scs scu se- sec see sek ser ses seu sk- skc ske skk skr sks sku sr- src sre srk srr srs ss- ssc sse ssk ssr sss ssu suc sue suk sur sus suu ucc uce uck ucr ucs ucu uec uee uer ues ukc uke ukk ukr uku ur- urc ure urk urr urs uru usc use usk usr uss usu uuc uue uur uus uuu