-er a-a a-c aaa aac aae aah aao aar aax ac- aca acc ace ach aco acr acx aea aec aee aeh aeo aer aex aha ahc ahe ahh aho ahr ahx aoa aoc aoe aoh aoo aor aox ar- ara arc are arh aro arr arx ax- axa axe axh axo axr axx c-- caa cac cae cah cao car cax cca ccc cce cch cco ccr ccx ce- cea cec cee ceh ceo cer cex ch- cha chc che chh cho chr chx co- coa coc coe coh coo cor cox cra crc cre crh cro crr crx cxc cxh cxo cxr cxx eaa eac eae eah eao ear eax ec- eca ecc ece ech eco ecr ecx eea eec eee eeo eer eex eha ehc ehe ehh eho ehr eo- eoa eoc eoe eoh eoo eor era erc ere erh ero err ex- exa exc exe exh exo exr exx haa hac hae hah hao har hax hca hcc hce hch hco hcr he- hea hec hee heh heo her hex hha hhc hhe hhh hho hhr hoa hoc hoe hoh hoo hor hox hr- hra hrc hre hrh hro hrr hxc oaa oac oae oah oao oar oax oc- oca occ och oco ocr ocx oea oec oee oeh oeo oer oex oha ohc ohe ohh oho ohr oo- ooa ooc ooh ooo oor oox or- ora orc ore orh oro orr orx ox- oxa oxc oxo oxx ra- raa rac rae rah rao rar rax rca rcc rce rch rco rcr rcx re- rea rec ree reh reo rer rex rh- rha rhc rhe rhh rho rhr roa roc roe roh roo ror rox rra rrc rrh rrr rxr xaa xac xar xch xcr xcx xee xer xex xoa xoc xoo xor xox xrc xrx xxo xxx