a-a a-t aaa aad aaf aan aat ad- ada add adf adn adt af- afa afd aff afn aft an- ana and anf ann ant at- ata atd atf atn att daa dad daf dan dat dda ddd ddf ddn ddt dfa dfd dff dfn dft dna dnd dnf dnn dnt dta dtd dtf dtn dtt faa fad faf fan fat fda fdd fdf fdn fdt ffa ffd fff ffn fft fna fnd fnf fnn fnt fta ftd ftf ftn ftt naa nad naf nan nat nda ndd ndf ndn ndt nfa nfd nff nfn nft nna nnf nnn nnt nta ntd ntf ntn ntt taa tad taf tan tat tda tdd tdf tdn tdt tfa tfd tff tfn tft tna tnd tnf tnn tnt tta ttd ttf ttn ttt