a-a a-b a-c a-t aaa aab aac aae aam aao aas aat ab- aba abb abc abe abm abo abs abt ac- aca acb acc ace acm aco acs act aea aeb aec aee aem aeo aes aet ama amb amc ame amm amo ams amt aoa aob aoc aoe aom aoo aos aot as- asa asb asc ase asm aso ass ast at- ata atb atc ate atm ato ats att baa bab bac bae bam bao bas bat bba bbb bbc bbe bbm bbo bbs bbt bca bcb bcc bce bcm bco bcs bct be- bea beb bec bee bem beo bes bet bma bmb bmc bme bmm bmo bms bmt boa bob boc boe bom boo bos bot bsa bsb bsc bse bsm bso bss bst bta btb btc bte btm bto bts btt c-- caa cab cac cae cam cao cas cat cba cbb cbc cbe cbm cbo cbs cbt cca ccb ccc cce ccm cco ccs cct ce- cea ceb cec cee cem ceo ces cet cma cmb cmc cme cmm cmo cms cmt co- coa cob coc coe com coo cos cot csa csb csc cse csm cso css cst cta ctb ctc cte ctm cto cts ctt eaa eab eac eae eam eao eas eat eba ebb ebc ebe ebm ebo ebs ebt ec- eca ecb ecc ece ecm eco ecs ect eea eeb eec eee eem eeo ees eet em- ema emb emc eme emm emo ems emt eo- eoa eob eoc eoe eom eoo eos eot es- esa esb esc ese esm eso ess est eta etb etc ete etm eto ets ett m-o maa mab mac mae mam mao mas mat mba mbb mbc mbe mbm mbo mbs mbt mc- mca mcb mcc mce mcm mco mcs mct mea meb mec mee mem meo mes met mma mmb mmc mme mmm mmo mms mmt moa mob moc moe mom moo mos mot msa msb msc mse msm mso mss mst mta mtb mtc mte mtm mto mts mtt oaa oab oac oae oam oao oas oat ob- oba obb obc obe obm obo obs obt oc- oca ocb occ ocm oco ocs oct oea oeb oec oee oem oeo oes oet om- oma omb omc ome omm omo oms omt oo- ooa oob ooc oom ooo oos oot os- osa osb osc ose osm oso oss ost ot- ota otb otc ote otm oto ots ott saa sab sac sae sam sao sas sat sba sbb sbc sbe sbm sbo sbs sbt sca scb scc sce scm sco scs sct se- sea seb sec see sem seo ses set sma smb smc sme smm smo sms smt soa sob soc soe som soo sos sot ss- ssa ssb ssc sse ssm sso sss sst sta stb stc ste stm sto sts stt taa tab tac tae tam tao tas tat tba tbb tbc tbe tbm tbo tbs tbt tca tcb tcc tce tcm tco tcs tct te- tea teb tec tee tem teo tes tet tma tmb tmc tme tmm tmo tms tmt to- toa tob toc toe tom too tos tot tsa tsb tsc tse tsm tso tss tst tta ttb ttc tte ttm tto tts ttt