-er c-- ccc cce ccf cck cco ccr ccs ccu ce- cec cee cef cek ceo cer ces ceu cfc cfe cff cfk cfo cfr cfs cfu ckc cko cks co- coc coe cof cok coo cor cos cou crc cre crf crk cro crr crs cru csc cse csf csk cso csr css csu cuc cue cuf cuk cuo cur cus cuu ec- ecc ece ecf eck eco ecr ecs ecu eec eee eef eek eeo eer ees ef- efc efe eff efo efr efs ekc eke ekf eko ekr eks eku eo- eoc eoe eof eok eoo eor eos eou erc ere erf erk ero err ers eru es- esc ese esf esk eso esr ess esu eu- euc eue euf eur eus fcc fce fcf fck fco fcr fcs fcu fec fee fef fek feo fer fes feu ffc ffe fff ffk ffo ffr ffs ffu fkc fkf fkk foc foe fof fok foo for fos fou frc fre frf frk fro frr frs fru fsc fse fsf fsk fso fsr fss fsu fue fuf fuk fuo fur fus fuu kcc kce kck kcr kcs kcu ke- kec kee kef kek keo ker kes kfc kff kfo kfs kfu kkc kke kkk kkr kks kku koc koe kof kok koo kor kos kou krc krf krk kro krr krs kru ksc kse ksf ksk kso ksr kss ksu kuc kue kuk kur kus kuu oc- occ ocf ock oco ocr ocs ocu oec oee oef oeo oer oes of- ofc ofe off ofo ofr ofs ofu okc oke okk oko okr oks oku oo- ooc oof ook ooo oor oos or- orc ore orf ork oro orr ors oru os- osc ose osf osk oso osr oss osu ou- ouc oue ouf ouk ouo our ous rcc rce rcf rco rcr rcs rcu re- rec ree ref rek reo rer res reu rfc rfe rff rfk rfo rfr rfs rfu rkc rke rkf rkk rko rks rku roc roe rof rok roo ror ros rou rrc rrf rrk rrr rrs rru rsc rse rsf rsk rso rsr rss rsu ruc rue ruf ruk ruo rur rus ruu scc sce scf sck sco scr scs scu se- sec see sef sek seo ser ses seu sfc sfe sff sfk sfo sfr sfs sfu sk- skc ske skf skk sko skr sks sku soc soe sof sok soo sor sos sou sr- src sre srf srk sro srr srs ss- ssc sse ssf ssk sso ssr sss ssu suc sue suf suk suo sur sus suu ucc uce ucf uck uco ucr ucs ucu uec uee uef uer ues ufc ufe uff ufo ufr ufs ufu ukc uke ukf ukk ukr uku uoc uoe uok uoo uor uos ur- urc ure urf urk uro urr urs uru usc use usf usk uso usr uss usu uuc uue uur uus uuu