-ic a-a a-b a-c a-i aaa aab aac aae aaf aai aao aas ab- aba abb abc abe abf abi abo abs ac- aca acb acc ace acf aci aco acs aea aeb aec aee aef aei aeo aes af- afa afb afc afe aff afi afo afs ai- aia aib aic aie aif aii aio ais aoa aob aoc aoe aof aoi aoo aos as- asa asb asc ase asf asi aso ass baa bab bac bae baf bai bao bas bba bbb bbc bbe bbf bbi bbo bbs bca bcb bcc bce bcf bci bco bcs be- bea beb bec bee bef bei beo bes bfa bfb bfc bfe bff bfi bfo bfs bi- bia bib bic bie bif bii bio bis boa bob boc boe bof boi boo bos bsa bsb bsc bse bsf bsi bso bss c-- caa cab cac cae caf cai cao cas cba cbb cbc cbe cbf cbi cbo cbs cca ccb ccc cce ccf cci cco ccs ce- cea ceb cec cee cef cei ceo ces cfa cfb cfc cfe cff cfi cfo cfs ci- cia cib cic cie cif cii cio cis co- coa cob coc coe cof coi coo cos csa csb csc cse csf csi cso css eaa eab eac eae eaf eai eao eas eba ebb ebc ebe ebf ebi ebo ebs ec- eca ecb ecc ece ecf eci eco ecs eea eeb eec eee eef eeo ees ef- efa efb efc efe eff efi efo efs eia eib eic eie eif eii eio eis eo- eoa eob eoc eoe eof eoi eoo eos es- esa esb esc ese esf esi eso ess faa fab fac fae faf fai fao fas fba fbb fbc fbe fbf fbi fbo fbs fca fcb fcc fce fcf fci fco fcs fea feb fec fee fef fei feo fes ffa ffc ffe fff ffi ffo ffs fia fib fic fie fif fii fis foa fob foc foe fof foi foo fos fsa fsb fsc fse fsf fsi fso fss i-f ia- iaa iab iac iae iaf iai iao ias iba ibb ibc ibe ibf ibi ibo ibs ica icb icc ice icf ici ico ics ie- iea iec iee ief iei ies ifa ifb ifc ife iff ifi ifo ifs iia iib iic iie iif iii iio iis io- ioa iob ioc ioe iof ioi ioo ios is- isa isb isc ise isf isi iso iss o-i oaa oab oac oae oaf oai oao oas ob- oba obb obc obe obf obi obo obs oc- oca ocb occ ocf oci oco ocs oea oeb oec oee oef oei oeo oes of- ofa ofb ofc ofe off ofi ofo ofs oia oib oic oie oif oii oio ois oo- ooa oob ooc oof ooi ooo oos os- osa osb osc ose osf osi oso oss saa sab sac sae saf sai sao sas sba sbb sbc sbe sbf sbi sbo sbs sca scb scc sce scf sci sco scs se- sea seb sec see sef sei seo ses sfa sfb sfc sfe sff sfi sfo sfs sia sib sic sie sif sii sio sis soa sob soc soe sof soi soo sos ss- ssa ssb ssc sse ssf ssi sso sss