-er -ic a-a a-c a-i aaa aac aae aag aai aao aar aax ac- aca acc ace acg aci aco acr acx aea aec aee aeg aei aeo aer aex ag- aga agc age agg agi ago agr agx ai- aia aic aie aig aii aio air aix aoa aoc aoe aog aoi aoo aor aox ar- ara arc are arg ari aro arr arx ax- axa axe axi axo axr axx c-- caa cac cae cag cai cao car cax cca ccc cce ccg cci cco ccr ccx ce- cea cec cee ceg cei ceo cer cex cga cgc cge cgg cgi cgo cgr ci- cia cic cie cig cii cio cir cix co- coa coc coe cog coi coo cor cox cra crc cre crg cri cro crr crx cxc cxi cxo cxr cxx eaa eac eae eag eai eao ear eax ec- eca ecc ece ecg eci eco ecr ecx eea eec eee eeg eeo eer eex ega egc ege egg egi ego egr egx eia eic eie eig eii eio eir eix eo- eoa eoc eoe eog eoi eoo eor era erc ere erg eri ero err ex- exa exc exe exi exo exr exx gaa gac gae gag gai gao gar gca gcc gce gcg gci gco gcr ge- gea gec gee geg gei geo ger gex gga ggc ggg ggi ggo ggr gia gic gie gig gii gio gir goa goc goe gog goi goo gor gox gra grc gre grg gri gro grr grx gxa ia- iaa iac iae iag iai iao iar ica icc ice icg ici ico icr ie- iea iec iee ieg iei ier iex iga igc ige igg igi igo igr iia iic iie iii iio iir iix io- ioa ioc ioe iog ioi ioo ior ir- ira irc ire irg iri iro irr irx ixc ixe ixi o-i oaa oac oae oag oai oao oar oax oc- oca occ ocg oci oco ocr ocx oea oec oee oeg oei oeo oer oex oga ogc oge ogg ogi ogo ogx oia oic oie oii oio oir oo- ooa ooc oog ooi ooo oor oox or- ora orc ore org ori oro orr orx ox- oxa oxc oxi oxo oxx ra- raa rac rae rag rai rao rar rax rca rcc rce rcg rci rco rcr rcx re- rea rec ree reg rei reo rer rex rga rgc rge rgg rgi rgo rgr rgx ria ric rie rig rii rio rir rix roa roc roe rog roi roo ror rox rra rrc rrg rri rrr rxr xaa xac xag xar xci xcr xcx xee xeg xer xex xge xgi xia xic xie xii xio xix xoa xoc xog xoi xoo xor xox xrc xrx xxi xxo xxx