-ic a-a a-b a-c a-i aaa aab aac aae aai aao aas ab- aba abb abc abe abi abo abs ac- aca acb acc ace aci aco acs aea aeb aec aee aei aeo aes ai- aia aib aic aie aii aio ais aoa aob aoc aoe aoi aoo aos as- asa asb asc ase asi aso ass baa bab bac bae bai bao bas bba bbb bbc bbe bbi bbo bbs bca bcb bcc bce bci bco bcs be- bea beb bec bee bei beo bes bi- bia bib bic bie bii bio bis boa bob boc boe boi boo bos bsa bsb bsc bse bsi bso bss c-- caa cab cac cae cai cao cas cba cbb cbc cbe cbi cbo cbs cca ccb ccc cce cci cco ccs ce- cea ceb cec cee cei ceo ces ci- cia cib cic cie cii cio cis co- coa cob coc coe coi coo cos csa csb csc cse csi cso css eaa eab eac eae eai eao eas eba ebb ebc ebe ebi ebo ebs ec- eca ecb ecc ece eci eco ecs eea eeb eec eee eeo ees eia eib eic eie eii eio eis eo- eoa eob eoc eoe eoi eoo eos es- esa esb esc ese esi eso ess ia- iaa iab iac iae iai iao ias iba ibb ibc ibe ibi ibo ibs ica icb icc ice ici ico ics ie- iea iec iee iei ies iia iib iic iie iii iio iis io- ioa iob ioc ioe ioi ioo ios is- isa isb isc ise isi iso iss o-i oaa oab oac oae oai oao oas ob- oba obb obc obe obi obo obs oc- oca ocb occ oci oco ocs oea oeb oec oee oei oeo oes oia oib oic oie oii oio ois oo- ooa oob ooc ooi ooo oos os- osa osb osc ose osi oso oss saa sab sac sae sai sao sas sba sbb sbc sbe sbi sbo sbs sca scb scc sce sci sco scs se- sea seb sec see sei seo ses sia sib sic sie sii sio sis soa sob soc soe soi soo sos ss- ssa ssb ssc sse ssi sso sss