-er -ic a-a a-b a-c a-i aaa aab aac aae aai aao aar aax ab- aba abb abc abe abi abo abr abx ac- aca acb acc ace aci aco acr acx aea aeb aec aee aei aeo aer aex ai- aia aib aic aie aii aio air aix aoa aob aoc aoe aoi aoo aor aox ar- ara arb arc are ari aro arr arx ax- axa axe axi axo axr axx baa bab bac bae bai bao bar bax bba bbb bbc bbe bbi bbo bbr bbx bca bcb bcc bce bci bco bcr bcx be- bea beb bec bee bei beo ber bex bi- bia bib bic bie bii bio bir bix boa bob boc boe boi boo bor box bra brb bre bri bro brr brx bxb bxi bxo bxx c-- caa cab cac cae cai cao car cax cba cbb cbc cbe cbi cbo cbr cbx cca ccb ccc cce cci cco ccr ccx ce- cea ceb cec cee cei ceo cer cex ci- cia cib cic cie cii cio cir cix co- coa cob coc coe coi coo cor cox cra crb crc cre cri cro crr crx cxc cxi cxo cxr cxx eaa eab eac eae eai eao ear eax eba ebb ebc ebe ebi ebo ebr ebx ec- eca ecb ecc ece eci eco ecr ecx eea eeb eec eee eeo eer eex eia eib eic eie eii eio eir eix eo- eoa eob eoc eoe eoi eoo eor era erb erc ere eri ero err ex- exa exc exe exi exo exr exx ia- iaa iab iac iae iai iao iar iba ibb ibc ibe ibi ibo ibr ibx ica icb icc ice ici ico icr ie- iea iec iee iei ier iex iia iib iic iie iii iio iir iix io- ioa iob ioc ioe ioi ioo ior ir- ira irb irc ire iri iro irr irx ixc ixe ixi o-i oaa oab oac oae oai oao oar oax ob- oba obb obc obe obi obo obr obx oc- oca ocb occ oci oco ocr ocx oea oeb oec oee oei oeo oer oex oia oib oic oie oii oio oir oo- ooa oob ooc ooi ooo oor oox or- ora orb orc ore ori oro orr orx ox- oxa oxb oxc oxi oxo oxx ra- raa rab rac rae rai rao rar rax rba rbb rbc rbe rbi rbo rbr rbx rca rcb rcc rce rci rco rcr rcx re- rea reb rec ree rei reo rer rex ria rib ric rie rii rio rir rix roa rob roc roe roi roo ror rox rra rrb rrc rri rrr rxr xaa xac xar xbc xbe xbr xbx xcb xci xcr xcx xee xer xex xia xic xie xii xio xix xoa xoc xoi xoo xor xox xrc xrx xxi xxo xxx