-er -ic a-a a-b a-c a-i aaa aab aac aae aai aar aax ab- aba abb abc abe abi abr abx ac- aca acb acc ace aci acr acx aea aeb aec aee aei aer aex ai- aia aib aic aie aii air aix ar- ara arb arc are ari arr arx ax- axa axe axi axr axx baa bab bac bae bai bar bax bba bbb bbc bbe bbi bbr bbx bca bcb bcc bce bci bcr bcx be- bea beb bec bee bei ber bex bi- bia bib bic bie bii bir bix bra brb bre bri brr brx bxb bxi bxx c-- caa cab cac cae cai car cax cba cbb cbc cbe cbi cbr cbx cca ccb ccc cce cci ccr ccx ce- cea ceb cec cee cei cer cex ci- cia cib cic cie cii cir cix cra crb crc cre cri crr crx cxc cxi cxr cxx eaa eab eac eae eai ear eax eba ebb ebc ebe ebi ebr ebx ec- eca ecb ecc ece eci ecr ecx eea eeb eec eee eer eex eia eib eic eie eii eir eix era erb erc ere eri err ex- exa exc exe exi exr exx ia- iaa iab iac iae iai iar iba ibb ibc ibe ibi ibr ibx ica icb icc ice ici icr ie- iea iec iee iei ier iex iia iib iic iie iii iir iix ir- ira irb irc ire iri irr irx ixc ixe ixi ra- raa rab rac rae rai rar rax rba rbb rbc rbe rbi rbr rbx rca rcb rcc rce rci rcr rcx re- rea reb rec ree rei rer rex ria rib ric rie rii rir rix rra rrb rrc rri rrr rxr xaa xac xar xbc xbe xbr xbx xcb xci xcr xcx xee xer xex xia xic xie xii xix xrc xrx xxi xxx