-er a-a a-c aaa aac aad aae aao aar aax ac- aca acc acd ace aco acr acx ad- ada adc add ade ado adr adx aea aec aed aee aeo aer aex aoa aoc aod aoe aoo aor aox ar- ara arc ard are aro arr arx ax- axa axe axo axr axx c-- caa cac cad cae cao car cax cca ccc ccd cce cco ccr ccx cda cdc cdd cde cdo cdr cdx ce- cea cec ced cee ceo cer cex co- coa coc cod coe coo cor cox cra crc crd cre cro crr crx cxc cxo cxr cxx daa dac dad dae dao dar dax dca dcc dcd dce dco dcr dcx dda ddc ddd dde ddo ddr ddx de- dea dec ded dee deo der dex doa doc dod doe doo dor dox dra drc drd dre dro drr drx dxc dxd dxo dxr dxx eaa eac ead eae eao ear eax ec- eca ecc ecd ece eco ecr ecx ed- eda edc edd ede edo edr edx eea eec eed eee eeo eer eex eo- eoa eoc eod eoe eoo eor era erc erd ere ero err ex- exa exc exd exe exo exr exx oaa oac oad oae oao oar oax oc- oca occ ocd oco ocr ocx oda odc odd ode odo odr oea oec oed oee oeo oer oex oo- ooa ooc ood ooo oor oox or- ora orc ord ore oro orr orx ox- oxa oxc oxo oxx ra- raa rac rad rae rao rar rax rca rcc rcd rce rco rcr rcx rda rdc rdd rde rdo rdr rdx re- rea rec red ree reo rer rex roa roc rod roe roo ror rox rra rrc rrd rrr rxr xaa xac xad xar xcd xcr xcx xda xdc xde xdr xed xee xer xex xoa xoc xod xoo xor xox xrc xrd xrx xxo xxx