a-a a-c a-t aaa aac aaf aan aat ac- aca acc acf acn act af- afa afc aff afn aft an- ana anc anf ann ant at- ata atc atf atn att c-- caa cac caf can cat cca ccc ccf ccn cct cfa cfc cff cfn cft cn- cna cnc cnf cnn cnt cta ctc ctf ctn ctt faa fac faf fan fat fca fcc fcf fcn fct ffa ffc fff ffn fft fna fnc fnf fnn fnt fta ftc ftf ftn ftt naa nac naf nan nat nca ncc ncf ncn nct nfa nfc nff nfn nft nna nnc nnf nnn nnt nta ntc ntf ntn ntt taa tac taf tan tat tca tcc tcf tcn tct tfa tfc tff tfn tft tna tnc tnf tnn tnt tta ttc ttf ttn ttt