a-a a-b a-c a-t aaa aab aac aad aan aas aat ab- aba abb abc abd abn abs abt ac- aca acb acc acd acn acs act ad- ada adb adc add adn ads adt an- ana anb anc and ann ans ant as- asa asb asc asd asn ass ast at- ata atb atc atd atn ats att baa bab bac bad ban bas bat bba bbb bbc bbd bbn bbs bbt bca bcb bcc bcd bcn bcs bct bda bdb bdc bdd bds bdt bna bnb bnc bnd bnn bns bnt bsa bsb bsc bsd bsn bss bst bta btb btc btd btn bts btt c-- caa cab cac cad can cas cat cba cbb cbc cbd cbn cbs cbt cca ccb ccc ccd ccn ccs cct cda cdb cdc cdd cdn cds cdt cn- cna cnb cnc cnd cnn cns cnt csa csb csc csd csn css cst cta ctb ctc ctd ctn cts ctt daa dab dac dad dan das dat dba dbb dbc dbd dbn dbs dbt dca dcb dcc dcd dcn dcs dct dda ddb ddc ddd ddn dds ddt dna dnb dnc dnd dnn dns dnt dsa dsb dsc dsd dsn dss dst dta dtb dtc dtd dtn dts dtt naa nab nac nad nan nas nat nba nbb nbc nbd nbn nbs nbt nca ncb ncc ncd ncn ncs nct nda ndb ndc ndd ndn nds ndt nna nnb nnc nnn nns nnt nsa nsb nsc nsd nsn nss nst nta ntb ntc ntd ntn nts ntt saa sab sac sad san sas sat sba sbb sbc sbd sbn sbs sbt sca scb scc scd scn scs sct sda sdb sdc sdd sdn sds sdt sna snb snc snd snn sns snt ss- ssa ssb ssc ssd ssn sss sst sta stb stc std stn sts stt taa tab tac tad tan tas tat tba tbb tbc tbd tbn tbs tbt tca tcb tcc tcd tcn tcs tct tda tdb tdc tdd tdn tds tdt tna tnb tnc tnd tnn tns tnt tsa tsb tsc tsd tsn tss tst tta ttb ttc ttd ttn tts ttt