-ic a-a a-b a-c a-i a-t aaa aab aac aae aai aao aas aat ab- aba abb abc abe abi abo abs abt ac- aca acb acc ace aci aco acs act aea aeb aec aee aei aeo aes aet ai- aia aib aic aie aii aio ais ait aoa aob aoc aoe aoi aoo aos aot as- asa asb asc ase asi aso ass ast at- ata atb atc ate ati ato ats att baa bab bac bae bai bao bas bat bba bbb bbc bbe bbi bbo bbs bbt bca bcb bcc bce bci bco bcs bct be- bea beb bec bee bei beo bes bet bi- bia bib bic bie bii bio bis bit boa bob boc boe boi boo bos bot bsa bsb bsc bse bsi bso bss bst bta btb btc bte bti bto bts btt c-- caa cab cac cae cai cao cas cat cba cbb cbc cbe cbi cbo cbs cbt cca ccb ccc cce cci cco ccs cct ce- cea ceb cec cee cei ceo ces cet ci- cia cib cic cie cii cio cis cit co- coa cob coc coe coi coo cos cot csa csb csc cse csi cso css cst cta ctb ctc cte cti cto cts ctt eaa eab eac eae eai eao eas eat eba ebb ebc ebe ebi ebo ebs ebt ec- eca ecb ecc ece eci eco ecs ect eea eeb eec eee eeo ees eet eia eib eic eie eii eio eis eit eo- eoa eob eoc eoe eoi eoo eos eot es- esa esb esc ese esi eso ess est eta etb etc ete eti eto ets ett ia- iaa iab iac iae iai iao ias iat iba ibb ibc ibe ibi ibo ibs ibt ica icb icc ice ici ico ics ict ie- iea iec iee iei ies iet iia iib iic iie iii iio iis iit io- ioa iob ioc ioe ioi ioo ios iot is- isa isb isc ise isi iso iss ist ita itb itc ite iti ito its itt o-i oaa oab oac oae oai oao oas oat ob- oba obb obc obe obi obo obs obt oc- oca ocb occ oci oco ocs oct oea oeb oec oee oei oeo oes oet oia oib oic oie oii oio ois oit oo- ooa oob ooc ooi ooo oos oot os- osa osb osc ose osi oso oss ost ot- ota otb otc ote oti oto ots ott saa sab sac sae sai sao sas sat sba sbb sbc sbe sbi sbo sbs sbt sca scb scc sce sci sco scs sct se- sea seb sec see sei seo ses set sia sib sic sie sii sio sis sit soa sob soc soe soi soo sos sot ss- ssa ssb ssc sse ssi sso sss sst sta stb stc ste sti sto sts stt taa tab tac tae tai tao tas tat tba tbb tbc tbe tbi tbo tbs tbt tca tcb tcc tce tci tco tcs tct te- tea teb tec tee tei teo tes tet tia tib tic tie tii tio tis tit to- toa tob toc toe toi too tos tot tsa tsb tsc tse tsi tso tss tst tta ttb ttc tte tti tto tts ttt