a-a a-c aaa aac aaf aag aan aao ac- aca acc acf acg acn aco af- afa afc aff afg afn afo ag- aga agc agf agg agn ago an- ana anc anf ang ann ano aoa aoc aof aog aon aoo c-- caa cac caf cag can cao cca ccc ccf ccg ccn cco cfa cfc cff cfg cfn cfo cga cgc cgg cgn cgo cn- cna cnc cnf cng cnn cno co- coa coc cof cog con coo faa fac faf fag fan fao fca fcc fcf fcg fcn fco ffa ffc fff ffg ffn ffo fga fgc fgf fgg fgn fna fnc fnf fng fnn foa foc fof fog fon foo gaa gac gaf gag gan gao gca gcc gcf gcg gcn gco gfa gfc gff gfo gga ggc ggg ggn ggo gna gnc gnf gnn gno goa goc gof gog gon goo naa nac naf nag nan nao nca ncc ncf ncg ncn nco nfa nfc nff nfn nfo nga ngc ngf ngg ngn ngo nna nnc nnf nng nnn nno no- noa noc nof nog non noo oaa oac oaf oag oan oao oc- oca occ ocf ocg ocn oco of- ofa ofc off ofg ofn ofo oga ogc ogf ogg ogn ogo on- ona onc onf ong onn ono oo- ooa ooc oof oog oon ooo