a-a a-b a-t aaa aab aag aao aas aat ab- aba abb abg abo abs abt ag- aga agb agg ago ags agt aoa aob aog aoo aos aot as- asa asb asg aso ass ast at- ata atb atg ato ats att baa bab bag bao bas bat bba bbb bbg bbo bbs bbt bga bgb bgg bgo bgs bgt boa bob bog boo bos bot bsa bsb bsg bso bss bst bta btb btg bto bts btt gaa gab gag gao gas gat gba gbg gbo gbs gbt gga ggb ggg ggo ggs ggt goa gob gog goo gos got gsa gsb gsg gso gss gst gta gtb gtg gto gts gtt oaa oab oag oao oas oat ob- oba obb obg obo obs obt oga ogg ogo ogs ogt oo- ooa oob oog ooo oos oot os- osa osb osg oso oss ost ot- ota otb otg oto ots ott saa sab sag sao sas sat sba sbb sbg sbo sbs sbt sga sgb sgg sgo sgs sgt soa sob sog soo sos sot ss- ssa ssb ssg sso sss sst sta stb stg sto sts stt taa tab tag tao tas tat tba tbb tbg tbo tbs tbt tga tgb tgg tgo tgs tgt to- toa tob tog too tos tot tsa tsb tsg tso tss tst tta ttb ttg tto tts ttt