-er c-- ccc cce cck ccr ccu ce- cec cee cek cer ceu ckc crc cre crk crr cru cuc cue cuk cur cuu ec- ecc ece eck ecr ecu eec eee eek eer ekc eke ekr eku erc ere erk err eru eu- euc eue eur kcc kce kck kcr kcu ke- kec kee kek ker kkc kke kkk kkr kku krc krk krr kru kuc kue kuk kur kuu rcc rce rcr rcu re- rec ree rek rer reu rkc rke rkk rku rrc rrk rrr rru ruc rue ruk rur ruu ucc uce uck ucr ucu uec uee uer ukc uke ukk ukr uku ur- urc ure urk urr uru uuc uue uur uuu