-er c-- ccc cce ccf cck ccr ccs ccu ce- cec cee cef cek cer ces ceu cfc cfe cff cfk cfr cfs cfu ckc cks crc cre crf crk crr crs cru csc cse csf csk csr css csu cuc cue cuf cuk cur cus cuu ec- ecc ece ecf eck ecr ecs ecu eec eee eef eek eer ees ef- efc efe eff efr efs ekc eke ekf ekr eks eku erc ere erf erk err ers eru es- esc ese esf esk esr ess esu eu- euc eue euf eur eus fcc fce fcf fck fcr fcs fcu fec fee fef fek fer fes feu ffc ffe fff ffk ffr ffs ffu fkc fkf fkk frc fre frf frk frr frs fru fsc fse fsf fsk fsr fss fsu fue fuf fuk fur fus fuu kcc kce kck kcr kcs kcu ke- kec kee kef kek ker kes kfc kff kfs kfu kkc kke kkk kkr kks kku krc krf krk krr krs kru ksc kse ksf ksk ksr kss ksu kuc kue kuk kur kus kuu rcc rce rcf rcr rcs rcu re- rec ree ref rek rer res reu rfc rfe rff rfk rfr rfs rfu rkc rke rkf rkk rks rku rrc rrf rrk rrr rrs rru rsc rse rsf rsk rsr rss rsu ruc rue ruf ruk rur rus ruu scc sce scf sck scr scs scu se- sec see sef sek ser ses seu sfc sfe sff sfk sfr sfs sfu sk- skc ske skf skk skr sks sku sr- src sre srf srk srr srs ss- ssc sse ssf ssk ssr sss ssu suc sue suf suk sur sus suu ucc uce ucf uck ucr ucs ucu uec uee uef uer ues ufc ufe uff ufr ufs ufu ukc uke ukf ukk ukr uku ur- urc ure urf urk urr urs uru usc use usf usk usr uss usu uuc uue uur uus uuu