-er -ic c-- ccc cce ccf cci cck cco ccr ccs ce- cec cee cef cei cek ceo cer ces cfc cfe cff cfi cfk cfo cfr cfs ci- cic cie cif cii cik cio cir cis ckc cki cko cks co- coc coe cof coi cok coo cor cos crc cre crf cri crk cro crr crs csc cse csf csi csk cso csr css ec- ecc ece ecf eci eck eco ecr ecs eec eee eef eek eeo eer ees ef- efc efe eff efi efo efr efs eic eie eif eii eik eio eir eis ekc eke ekf eki eko ekr eks eo- eoc eoe eof eoi eok eoo eor eos erc ere erf eri erk ero err ers es- esc ese esf esi esk eso esr ess fcc fce fcf fci fck fco fcr fcs fec fee fef fei fek feo fer fes ffc ffe fff ffi ffk ffo ffr ffs fic fie fif fii fik fir fis fkc fkf fki fkk foc foe fof foi fok foo for fos frc fre frf fri frk fro frr frs fsc fse fsf fsi fsk fso fsr fss i-f icc ice icf ici ick ico icr ics ie- iec iee ief iei iek ier ies ifc ife iff ifi ifo ifr ifs iic iie iif iii iio iir iis ikc ike ikf iki ikk iko ikr iks io- ioc ioe iof ioi ioo ior ios ir- irc ire irf iri irk iro irr irs is- isc ise isf isi isk iso isr iss kcc kce kci kck kcr kcs ke- kec kee kef kei kek keo ker kes kfc kff kfi kfo kfs kic kie kif kii kik kio kir kis kkc kke kki kkk kkr kks koc koe kof koi kok koo kor kos krc krf kri krk kro krr krs ksc kse ksf ksi ksk kso ksr kss o-i oc- occ ocf oci ock oco ocr ocs oec oee oef oei oeo oer oes of- ofc ofe off ofi ofo ofr ofs oic oie oif oii oik oio oir ois okc oke oki okk oko okr oks oo- ooc oof ooi ook ooo oor oos or- orc ore orf ori ork oro orr ors os- osc ose osf osi osk oso osr oss rcc rce rcf rci rco rcr rcs re- rec ree ref rei rek reo rer res rfc rfe rff rfi rfk rfo rfr rfs ric rie rif rii rik rio rir ris rkc rke rkf rkk rko rks roc roe rof roi rok roo ror ros rrc rrf rri rrk rrr rrs rsc rse rsf rsi rsk rso rsr rss scc sce scf sci sck sco scr scs se- sec see sef sei sek seo ser ses sfc sfe sff sfi sfk sfo sfr sfs sic sie sif sii sik sio sir sis sk- skc ske skf ski skk sko skr sks soc soe sof soi sok soo sor sos sr- src sre srf sri srk sro srr srs ss- ssc sse ssf ssi ssk sso ssr sss