-er a-a a-c aaa aac aae aak aam aar aas ac- aca acc ace ack acm acr acs aea aec aee aek aem aer aes aka akc ake akk akm akr aks ama amc ame amk amm amr ams ar- ara arc are ark arm arr ars as- asa asc ase ask asm asr ass c-- caa cac cae cak cam car cas cca ccc cce cck ccm ccr ccs ce- cea cec cee cek cem cer ces cka ckc ckm cks cma cmc cme cmk cmm cmr cms cra crc cre crk crm crr crs csa csc cse csk csm csr css eaa eac eae eak eam ear eas ec- eca ecc ece eck ecm ecr ecs eea eec eee eek eem eer ees eka ekc eke ekr eks em- ema emc eme emk emm emr ems era erc ere erk erm err ers es- esa esc ese esk esm esr ess ka- kaa kac kae kak kam kar kas kca kcc kce kck kcm kcr kcs ke- kea kec kee kek kem ker kes kkc kke kkk kkm kkr kks kma kmc kme kmk kmm kms kra krc krk krr krs ksa ksc kse ksk ksm ksr kss m-r maa mac mae mak mam mar mas mc- mca mcc mce mck mcm mcr mcs mea mec mee mek mem mer mes mka mkc mke mkk mkm mkr mks mma mmc mme mmk mmm mmr mms mra mrc mre mrk mrm mrr mrs msa msc mse msk msm msr mss ra- raa rac rae rak ram rar ras rca rcc rce rcm rcr rcs re- rea rec ree rek rem rer res rkc rke rkk rkm rks rma rmc rme rmm rmr rms rra rrc rrk rrm rrr rrs rsa rsc rse rsk rsm rsr rss saa sac sae sak sam sar sas sca scc sce sck scm scr scs se- sea sec see sek sem ser ses sk- ska skc ske skk skm skr sks sma smc sme smk smm smr sms sr- sra src sre srk srm srr srs ss- ssa ssc sse ssk ssm ssr sss