-er -ey a-a a-c aaa aac aae aao aar aax aay ac- aca acc ace aco acr acx acy aea aec aee aeo aer aex aey aoa aoc aoe aoo aor aox ar- ara arc are aro arr arx ary ax- axa axe axo axr axx ay- aya ayc aye ayo ayr ayx c-- caa cac cae cao car cax cay cca ccc cce cco ccr ccx ce- cea cec cee ceo cer cex cey co- coa coc coe coo cor cox coy cra crc cre cro crr crx cry cxc cxo cxr cxx cya cyc cye cyo cyr eaa eac eae eao ear eax ec- eca ecc ece eco ecr ecx eea eec eee eeo eer eex eey eo- eoa eoc eoe eoo eor era erc ere ero err ery ex- exa exc exe exo exr exx exy eya eyc eye eyo eyr oaa oac oae oao oar oax oc- oca occ oco ocr ocx oea oec oee oeo oer oex oey oo- ooa ooc ooo oor oox or- ora orc ore oro orr orx ory ox- oxa oxc oxo oxx oxy oya oye oyo ra- raa rac rae rao rar rax ray rca rcc rce rco rcr rcx re- rea rec ree reo rer rex rey roa roc roe roo ror rox roy rra rrc rrr rxr ry- rya ryc rye ryo ryr ryy xaa xac xar xcr xcx xee xer xex xoa xoc xoo xor xox xrc xrx xry xxo xxx xxy xyr xyy yaa yac yae yao yar yax yay yca ycc yce yco ycy yea yec yee yeo yer yex yey yoc yoe yoo yor yox yoy yra yrc yre yro yxa yxe yxy yyc yye yyy