-er c-- ccc cce ccf cck ccl ccr ccs ce- cec cee cef cek cel cer ces cfc cfe cff cfk cfl cfr cfs ckc cks cl- clc cle clf clk cll clr cls crc cre crf crk crl crr crs csc cse csf csk csl csr css ec- ecc ece ecf eck ecl ecr ecs eec eee eef eek eel eer ees ef- efc efe eff efl efr efs ekc eke ekf ekl ekr eks elc ele elf elk ell elr els erc ere erf erk erl err ers es- esc ese esf esk esl esr ess fcc fce fcf fck fcl fcr fcs fec fee fef fek fel fer fes ffc ffe fff ffk ffl ffr ffs fkc fkf fkk fkl flc fle flf fll flr fls frc fre frf frk frl frr frs fsc fse fsf fsk fsl fsr fss kcc kce kck kcl kcr kcs ke- kec kee kef kek kel ker kes kfc kff kfs kkc kke kkk kkl kkr kks kl- klc klf klr kls krc krf krk krl krr krs ksc kse ksf ksk ksl ksr kss lcc lce lcf lck lcl lcr lcs lec lee lef lek lel ler les lfc lfe lff lfk lfl lfr lfs lkl lkr lks llc lle llf llk lll llr lls lrc lrf lrk lrr lrs lsc lse lsf lsk lsl lsr lss rcc rce rcf rcl rcr rcs re- rec ree ref rek rel rer res rfc rfe rff rfk rfl rfr rfs rkc rke rkf rkk rks rlc rle rlf rll rlr rls rrc rrf rrk rrl rrr rrs rsc rse rsf rsk rsl rsr rss scc sce scf sck scl scr scs se- sec see sef sek sel ser ses sfc sfe sff sfk sfl sfr sfs sk- skc ske skf skk skl skr sks slc sle slf slk sll slr sls sr- src sre srf srk srl srr srs ss- ssc sse ssf ssk ssl ssr sss