-er a-a a-c aaa aac aae aam aan aar aax ac- aca acc ace acm acn acr acx aea aec aee aem aen aer aex ama amc ame amm amn amr amx an- ana anc ane anm ann anr anx ar- ara arc are arm arn arr arx ax- axa axe axm axn axr axx c-- caa cac cae cam can car cax cca ccc cce ccm ccn ccr ccx ce- cea cec cee cem cen cer cex cma cmc cme cmm cmn cmr cmx cn- cna cnc cne cnm cnn cnr cnx cra crc cre crm crn crr crx cxc cxr cxx eaa eac eae eam ean ear eax ec- eca ecc ece ecm ecn ecr ecx eea eec eee eem een eer eex em- ema emc eme emm emn emr emx en- ena enc ene enm enn enr era erc ere erm ern err ex- exa exc exe exr exx m-r maa mac mae mam man mar max mc- mca mcc mce mcm mcn mcr mcx mea mec mee mem men mer mex mma mmc mme mmm mmn mmr mmx mna mnc mne mnm mnn mnr mra mrc mre mrm mrn mrr mrx mxa mxc mxn mxr naa nac nae nam nan nar nax nca ncc nce ncm ncn ncr ncx ne- nea nec nee nem nen ner nex nma nmc nme nmm nmn nmr nna nnc nne nnm nnn nra nrc nre nrm nrn nrr nrx nxc ra- raa rac rae ram ran rar rax rca rcc rce rcm rcn rcr rcx re- rea rec ree rem ren rer rex rma rmc rme rmm rmn rmr rmx rna rnc rnm rnn rnr rra rrc rrm rrn rrr rxr xaa xac xam xan xar xcr xcx xee xem xen xer xex xma xmc xmm xmr xmx xna xnc xrc xrx xxx