-ic a-a a-b a-c a-i a-t aaa aab aac aae aai aas aat ab- aba abb abc abe abi abs abt ac- aca acb acc ace aci acs act aea aeb aec aee aei aes aet ai- aia aib aic aie aii ais ait as- asa asb asc ase asi ass ast at- ata atb atc ate ati ats att baa bab bac bae bai bas bat bba bbb bbc bbe bbi bbs bbt bca bcb bcc bce bci bcs bct be- bea beb bec bee bei bes bet bi- bia bib bic bie bii bis bit bsa bsb bsc bse bsi bss bst bta btb btc bte bti bts btt c-- caa cab cac cae cai cas cat cba cbb cbc cbe cbi cbs cbt cca ccb ccc cce cci ccs cct ce- cea ceb cec cee cei ces cet ci- cia cib cic cie cii cis cit csa csb csc cse csi css cst cta ctb ctc cte cti cts ctt eaa eab eac eae eai eas eat eba ebb ebc ebe ebi ebs ebt ec- eca ecb ecc ece eci ecs ect eea eeb eec eee ees eet eia eib eic eie eii eis eit es- esa esb esc ese esi ess est eta etb etc ete eti ets ett ia- iaa iab iac iae iai ias iat iba ibb ibc ibe ibi ibs ibt ica icb icc ice ici ics ict ie- iea iec iee iei ies iet iia iib iic iie iii iis iit is- isa isb isc ise isi iss ist ita itb itc ite iti its itt saa sab sac sae sai sas sat sba sbb sbc sbe sbi sbs sbt sca scb scc sce sci scs sct se- sea seb sec see sei ses set sia sib sic sie sii sis sit ss- ssa ssb ssc sse ssi sss sst sta stb stc ste sti sts stt taa tab tac tae tai tas tat tba tbb tbc tbe tbi tbs tbt tca tcb tcc tce tci tcs tct te- tea teb tec tee tei tes tet tia tib tic tie tii tis tit tsa tsb tsc tse tsi tss tst tta ttb ttc tte tti tts ttt