a-a a-b a-c a-t aaa aab aac aae aaf aao aas aat ab- aba abb abc abe abf abo abs abt ac- aca acb acc ace acf aco acs act aea aeb aec aee aef aeo aes aet af- afa afb afc afe aff afo afs aft aoa aob aoc aoe aof aoo aos aot as- asa asb asc ase asf aso ass ast at- ata atb atc ate atf ato ats att baa bab bac bae baf bao bas bat bba bbb bbc bbe bbf bbo bbs bbt bca bcb bcc bce bcf bco bcs bct be- bea beb bec bee bef beo bes bet bfa bfb bfc bfe bff bfo bfs bft boa bob boc boe bof boo bos bot bsa bsb bsc bse bsf bso bss bst bta btb btc bte btf bto bts btt c-- caa cab cac cae caf cao cas cat cba cbb cbc cbe cbf cbo cbs cbt cca ccb ccc cce ccf cco ccs cct ce- cea ceb cec cee cef ceo ces cet cfa cfb cfc cfe cff cfo cfs cft co- coa cob coc coe cof coo cos cot csa csb csc cse csf cso css cst cta ctb ctc cte ctf cto cts ctt eaa eab eac eae eaf eao eas eat eba ebb ebc ebe ebf ebo ebs ebt ec- eca ecb ecc ece ecf eco ecs ect eea eeb eec eee eef eeo ees eet ef- efa efb efc efe eff efo efs eft eo- eoa eob eoc eoe eof eoo eos eot es- esa esb esc ese esf eso ess est eta etb etc ete etf eto ets ett faa fab fac fae faf fao fas fat fba fbb fbc fbe fbf fbo fbs fbt fca fcb fcc fce fcf fco fcs fct fea feb fec fee fef feo fes fet ffa ffc ffe fff ffo ffs fft foa fob foc foe fof foo fos fot fsa fsb fsc fse fsf fso fss fst fta ftb ftc fte ftf fto fts ftt oaa oab oac oae oaf oao oas oat ob- oba obb obc obe obf obo obs obt oc- oca ocb occ ocf oco ocs oct oea oeb oec oee oef oeo oes oet of- ofa ofb ofc ofe off ofo ofs oft oo- ooa oob ooc oof ooo oos oot os- osa osb osc ose osf oso oss ost ot- ota otb otc ote otf oto ots ott saa sab sac sae saf sao sas sat sba sbb sbc sbe sbf sbo sbs sbt sca scb scc sce scf sco scs sct se- sea seb sec see sef seo ses set sfa sfb sfc sfe sff sfo sfs sft soa sob soc soe sof soo sos sot ss- ssa ssb ssc sse ssf sso sss sst sta stb stc ste stf sto sts stt taa tab tac tae taf tao tas tat tba tbb tbc tbe tbf tbo tbs tbt tca tcb tcc tce tcf tco tcs tct te- tea teb tec tee tef teo tes tet tfa tfb tfc tfe tff tfo tfs tft to- toa tob toc toe tof too tos tot tsa tsb tsc tse tsf tso tss tst tta ttb ttc tte ttf tto tts ttt